feat(fleet): enforce generated environment boundary (#772)

docs/SITEMAP.md

@@ -1,5 +1,12 @@
 # Documentation Sitemap
 
+## Fleet configuration management
+
+- [Generated environment boundary](fleet/reference/generated-env-boundary.md) — roster-derived launch projection, strict local data, legacy quarantine, and downstream interface evidence.
+- [Roster v2 structural contract](fleet/reference/roster-v2-fields.md) — local-tmux schema v2 parsing and structural validation.
+- [Role classes and authority](fleet/reference/role-classes.md) — canonical role resolver and protected authority boundaries.
+- [Executable asset dispositions](fleet/migration/example-profile-disposition.md) — shipped v1 fixture/profile/service validation posture.
+
 ## Official channel plugins
 
 - [Channel protocol architecture](architecture/channel-protocol.md) — shared lifecycle, message, stable-route, authorization, and response-target contracts.

docs/TASKS.md

@@ -52,20 +52,20 @@ Active workstream is **W1 — Federation v1**. Workers should:
 > the repository quality gates, independent code and security review, terminal-green CI, and
 > the applicable acceptance evidence before merge. Issue #758 remains open until M5 closes.
 
-| id         | status      | description                                                                                                                                                            | issue | agent  | repo              | branch                                  | depends_on                                     | estimate | notes                                                                                                            |
+| id         | status      | description                                                                                                                                                            | issue | agent         | repo              | branch                                  | depends_on                                     | estimate | notes                                                                                                                    |
-| ---------- | ----------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----- | ------ | ----------------- | --------------------------------------- | ---------------------------------------------- | -------- | ---------------------------------------------------------------------------------------------------------------- |
+| ---------- | ----------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----- | ------------- | ----------------- | --------------------------------------- | ---------------------------------------------- | -------- | ------------------------------------------------------------------------------------------------------------------------ |
-| FCM-M0-001 | in-progress | Publish normative PRD requirements/acceptance criteria, this M0–M5 DAG, docs-IA checklist, and legacy example/profile disposition inventory; no implementation changes | #758  | sonnet | mosaicstack/stack | `docs/758-fleet-config-management`      | —                                              | 18K      | M0 exit: approved docs; every shipped example/profile/service preset classified; docs-only PR                    |
+| FCM-M0-001 | done        | Publish normative PRD requirements/acceptance criteria, this M0–M5 DAG, docs-IA checklist, and legacy example/profile disposition inventory; no implementation changes | #758  | sonnet        | mosaicstack/stack | `docs/758-fleet-config-management`      | —                                              | 18K      | Merged via #760 (`c32d85a`); parent #758 intentionally remains open through M5                                           |
-| FCM-M1-001 | not-started | Implement narrow local-tmux v2 roster structural contract/compiler with YAML/JSON canonicalization and schema/parser parity tests                                      | #758  | codex  | mosaicstack/stack | `feat/758-roster-v2-compiler`           | FCM-M0-001                                     | 30K      | No lifecycle, remote, connector, secret, channel, or gateway work                                                |
+| FCM-M1-001 | done        | Implement narrow local-tmux v2 roster structural contract/compiler with YAML/JSON canonicalization and schema/parser parity tests                                      | #758  | coder0        | mosaicstack/stack | `feat/758-roster-v2-compiler`           | FCM-M0-001                                     | 30K      | #764 squash `aa5b43b`; exact-head RoR and PR/main terminal-green CI; no lifecycle or live mutation                       |
-| FCM-M1-002 | not-started | Reuse existing profile/persona/provision resolver for roster semantics; add canonical class/authority validation and approved aliases                                  | #758  | codex  | mosaicstack/stack | `feat/758-shared-role-resolution`       | FCM-M0-001                                     | 25K      | Validator is certificate-only; merge-gate remains sole merge authority                                           |
+| FCM-M1-002 | in-progress | Reuse existing profile/persona/provision resolver for roster semantics; add canonical class/authority validation and approved aliases                                  | #758  | native-sonnet | mosaicstack/stack | `feat/758-shared-role-resolution`       | FCM-M0-001                                     | 25K      | Started 2026-07-14 from `aa5b43b`; one shared resolver only; validator certificate-only; merge-gate sole merge authority |
-| FCM-M1-003 | not-started | Convert the M0 legacy inventory into executable example/profile/service-preset validation and explicit v1-version/retirement checks                                    | #758  | codex  | mosaicstack/stack | `test/758-example-profile-dispositions` | FCM-M1-001, FCM-M1-002                         | 20K      | Every shipped artifact must validate, be versioned v1, or be retired with replacement                            |
+| FCM-M1-003 | not-started | Convert the M0 legacy inventory into executable example/profile/service-preset validation and explicit v1-version/retirement checks                                    | #758  | codex         | mosaicstack/stack | `test/758-example-profile-dispositions` | FCM-M1-001, FCM-M1-002                         | 20K      | Every shipped artifact must validate, be versioned v1, or be retired with replacement                                    |
-| FCM-M2-001 | not-started | Migrate generic launch chain to deterministic `.env.generated` plus strict data-only `.env.local`; quarantine forbidden legacy keys                                    | #758  | codex  | mosaicstack/stack | `feat/758-generated-env-boundary`       | FCM-M1-001, FCM-M1-002                         | 30K      | No arbitrary command compatibility path; diagnostics expose key names/hashes only                                |
+| FCM-M2-001 | not-started | Migrate generic launch chain to deterministic `.env.generated` plus strict data-only `.env.local`; quarantine forbidden legacy keys                                    | #758  | codex         | mosaicstack/stack | `feat/758-generated-env-boundary`       | FCM-M1-001, FCM-M1-002                         | 30K      | No arbitrary command compatibility path; diagnostics expose key names/hashes only                                        |
-| FCM-M2-002 | not-started | Add generation-guarded local fleet agent create/get/update/delete mutations with plan/dry-run, atomic roster writes, and recovery output                               | #758  | codex  | mosaicstack/stack | `feat/758-fleet-agent-crud`             | FCM-M1-001, FCM-M2-001                         | 30K      | Fresh create persists stopped unless explicit persisted start                                                    |
+| FCM-M2-002 | not-started | Add generation-guarded local fleet agent create/get/update/delete mutations with plan/dry-run, atomic roster writes, and recovery output                               | #758  | codex         | mosaicstack/stack | `feat/758-fleet-agent-crud`             | FCM-M1-001, FCM-M2-001                         | 30K      | Fresh create persists stopped unless explicit persisted start                                                            |
-| FCM-M3-001 | not-started | Implement local roster-owned reconcile/apply plus lifecycle/status/verify/doctor contracts and stable JSON/exit codes                                                  | #758  | codex  | mosaicstack/stack | `feat/758-local-reconciler`             | FCM-M2-001, FCM-M2-002                         | 35K      | Exact systemd/tmux ownership; remote/schema-only entries are inventory only                                      |
+| FCM-M3-001 | not-started | Implement local roster-owned reconcile/apply plus lifecycle/status/verify/doctor contracts and stable JSON/exit codes                                                  | #758  | codex         | mosaicstack/stack | `feat/758-local-reconciler`             | FCM-M2-001, FCM-M2-002                         | 35K      | Exact systemd/tmux ownership; remote/schema-only entries are inventory only                                              |
-| FCM-M3-002 | not-started | Add isolated systemd/tmux lifecycle, drift, socket, unmanaged-session, crash, and rollback acceptance coverage                                                         | #758  | sonnet | mosaicstack/stack | `test/758-reconciler-lifecycle-gates`   | FCM-M3-001                                     | 25K      | Proves stopped-state preservation and zero fuzzy destructive targeting                                           |
+| FCM-M3-002 | not-started | Add isolated systemd/tmux lifecycle, drift, socket, unmanaged-session, crash, and rollback acceptance coverage                                                         | #758  | sonnet        | mosaicstack/stack | `test/758-reconciler-lifecycle-gates`   | FCM-M3-001                                     | 25K      | Proves stopped-state preservation and zero fuzzy destructive targeting                                                   |
-| FCM-M4-001 | not-started | Implement field-complete v1-to-v2 inventory/preview/migrator with alias, lifecycle, env-quarantine, and remote/connector disposition evidence                          | #758  | codex  | mosaicstack/stack | `feat/758-v1-v2-migrator`               | FCM-M1-003, FCM-M3-001                         | 35K      | Preview first; no unreviewed lifecycle inference                                                                 |
+| FCM-M4-001 | not-started | Implement field-complete v1-to-v2 inventory/preview/migrator with alias, lifecycle, env-quarantine, and remote/connector disposition evidence                          | #758  | codex         | mosaicstack/stack | `feat/758-v1-v2-migrator`               | FCM-M1-003, FCM-M3-001                         | 35K      | Preview first; no unreviewed lifecycle inference                                                                         |
-| FCM-M4-002 | not-started | Add reversible canary migration, rollback, stale-projection/orphan classification, and current-host 9-managed/3-unmanaged fixture coverage                             | #758  | sonnet | mosaicstack/stack | `test/758-migration-rollback-gates`     | FCM-M4-001, FCM-M3-002                         | 25K      | Never starts a previously stopped agent or kills an unproven unmanaged session                                   |
+| FCM-M4-002 | not-started | Add reversible canary migration, rollback, stale-projection/orphan classification, and current-host 9-managed/3-unmanaged fixture coverage                             | #758  | sonnet        | mosaicstack/stack | `test/758-migration-rollback-gates`     | FCM-M4-001, FCM-M3-002                         | 25K      | Never starts a previously stopped agent or kills an unproven unmanaged session                                           |
-| FCM-M5-001 | not-started | Deliver the accepted fleet documentation IA, how-to/operations/migration references, and link/example validation                                                       | #758  | haiku  | mosaicstack/stack | `docs/758-fleet-config-operator-docs`   | FCM-M1-003, FCM-M2-002, FCM-M3-001, FCM-M4-001 | 24K      | Must close every checklist item or record an approved deferral                                                   |
+| FCM-M5-001 | not-started | Deliver the accepted fleet documentation IA, how-to/operations/migration references, and link/example validation                                                       | #758  | haiku         | mosaicstack/stack | `docs/758-fleet-config-operator-docs`   | FCM-M1-003, FCM-M2-002, FCM-M3-001, FCM-M4-001 | 24K      | Must close every checklist item or record an approved deferral                                                           |
-| FCM-M5-002 | not-started | Package/update asset-drift checks, rolling local canary, independent validation certificate, and release evidence                                                      | #758  | sonnet | mosaicstack/stack | `feat/758-fleet-config-release-gate`    | FCM-M3-002, FCM-M4-002, FCM-M5-001             | 30K      | Final #758 gate: quality, independent code/security review, validator certificate, merge-gate approval, green CI |
+| FCM-M5-002 | not-started | Package/update asset-drift checks, rolling local canary, independent validation certificate, and release evidence                                                      | #758  | sonnet        | mosaicstack/stack | `feat/758-fleet-config-release-gate`    | FCM-M3-002, FCM-M4-002, FCM-M5-001             | 30K      | Final #758 gate: quality, independent code/security review, validator certificate, merge-gate approval, green CI         |
 
 ## Thin-core prompt diet (#528) — feat/contract-thin-core
 

docs/fleet/FLEET-LAUNCH.md

@@ -1,114 +1,77 @@
 # Fleet Launch Runbook
 
-How every Mosaic fleet agent — workers **and** the orchestrator — is launched, and how to
+The local fleet roster is the sole writable desired-state authority for membership and launch policy.
-configure each one. The guiding principle: **one roster-driven launcher**. There is no bespoke
+Generated environment files are rebuildable projections, not an operator-editable command surface.
-per-agent launch script; the roster plus per-agent `.env` files are the single source of launch
-config.
 
-## The launch chain
+## Launch chain
 
-| Layer            | File                                              | Responsibility                                                                                                                                              |
+| Layer               | Responsibility                                                                                                                  |
-| ---------------- | ------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| ------------------- | ------------------------------------------------------------------------------------------------------------------------------- |
-| systemd unit     | `mosaic-agent@<role>.service`                     | One templated unit per role; `ExecStart` runs the session launcher with the instance name `%i`. Defaults `MOSAIC_AGENT_RUNTIME=pi`, `MOSAIC_AGENT_NAME=%i`. |
+| Roster              | `fleet/roster.yaml` supplies the agent name, class, supported runtime, model, reasoning, tool policy, workdir, and tmux socket. |
-| session launcher | `tools/fleet/start-agent-session.sh <role>`       | Builds the launch command, opens the tmux pane, wires the heartbeat.                                                                                        |
+| Projection writer   | Renders deterministic `fleet/agents/<name>.env.generated` from the roster.                                                      |
-| launch command   | `mosaic yolo <runtime>` (or a per-agent override) | Replaces the pane's foreground process with the runtime, fully seeded.                                                                                      |
+| Optional local data | Reads a strict, data-only `fleet/agents/<name>.env.local`; it cannot shadow generated keys.                                     |
-| seeding          | `mosaic`'s `composeContract()`                    | Injects the Constitution/USER/TOOLS/runtime contract, `*.local` overlays, **and** the Fleet-Comms cheat-sheet — all via `--append-system-prompt`.           |
+| systemd             | Starts the launcher with `env -i` and fixed bootstrap data. It does not preload either environment file.                        |
+| session launcher    | Validates generated and local data before it queries, creates, or stops an exact tmux session.                                  |
+| runtime launch      | Derives the fixed `mosaic yolo <runtime>` argument array from validated roster data, then seeds the runtime contract.           |
 
-Per-agent overrides live in `fleet/agents/<role>.env`, generated from `roster.yaml` by
+The launcher never `source`s or `eval`s an environment file and never accepts an environment-supplied
-`generateAgentEnv` (`packages/mosaic/src/commands/fleet.ts`) and consumed by the launcher.
+command. `MOSAIC_AGENT_COMMAND`, command/channel overrides, unknown keys, generated-key shadowing,
+secret-like key names, duplicate keys, comments, quoted/export syntax, and unsafe values are rejected.
 
-## Worker launch path (default)
+## Generated and local files
 
-1. `roster.yaml` carries each agent's `runtime` and optional `model_hint`.
+`<name>.env.generated` is complete, deterministic, and written only by Mosaic. Its ordered keys are:
-2. `generateAgentEnv` emits `fleet/agents/<role>.env` with `MOSAIC_AGENT_NAME`,
-   `MOSAIC_AGENT_RUNTIME`, and `MOSAIC_AGENT_MODEL`.
-3. `start-agent-session.sh` has no `MOSAIC_AGENT_COMMAND` set, so it falls through to the default
-   (line ~44):
-   ```sh
-   MOSAIC_AGENT_COMMAND="mosaic yolo $MOSAIC_AGENT_RUNTIME${MOSAIC_AGENT_MODEL:+ --model $MOSAIC_AGENT_MODEL}"
-   ```
-4. The launcher bakes `MOSAIC_AGENT_NAME` into the pane command (line ~118), so `composeContract`
-   can inject the Fleet-Comms cheat-sheet for that role.
 
-That is the whole worker path: roster → `.env` → `mosaic yolo <runtime>` → seeded pane.
+```dotenv
-
+MOSAIC_AGENT_NAME=<roster name>
-## Orchestrator fold (PATH A — ships today)
+MOSAIC_AGENT_CLASS=<roster class>
-
+MOSAIC_AGENT_RUNTIME=<roster runtime>
-The orchestrator is **just another roster agent** launched through the canonical path — not a
+MOSAIC_AGENT_MODEL=<roster model hint>
-snowflake script.
+MOSAIC_AGENT_REASONING=<roster reasoning>
-
+MOSAIC_AGENT_TOOL_POLICY=<roster tool policy>
-| Piece              | Value                               |
+MOSAIC_AGENT_WORKDIR=<absolute roster work directory>
-| ------------------ | ----------------------------------- |
+MOSAIC_TMUX_SOCKET=<roster socket or empty>
-| host-side launcher | `orchestrator-launch.sh`            |
-| systemd unit       | `mosaic-fleet-orchestrator.service` |
-| tmux session       | `orchestrator` (role-named)         |
-
-Set its launch command via `fleet/agents/orchestrator.env`:
-
-```sh
-MOSAIC_AGENT_COMMAND='mosaic yolo claude --channels plugin:discord@<channel>'
 ```
 
-When `MOSAIC_AGENT_COMMAND` is set, `start-agent-session.sh`'s `if [ -z "$MOSAIC_AGENT_COMMAND" ]`
+The generated launch contract supports `claude`, `codex`, `opencode`, and `pi`. `mosaic fleet add`
-guard (line ~41) is false, so the line-44 default — **including its hardcoded `yolo`** — is skipped
+rejects another runtime before it writes the roster or modifies generated, local, or quarantine state.
-entirely. The override fully controls the runtime and flags. Routing through `mosaic yolo claude`
+The legacy dogfood stub remains an observability-only canary on its separate `mosaic-factory` socket;
-(rather than a raw `claude` invocation) is what gives the orchestrator the same full
+it has no generated-launch adapter and cannot be added through this path.
-`composeContract` seeding + Fleet-Comms cheat-sheet as every worker, with `--channels` and any
-other flags passed straight through to the `claude` binary.
 
-## Launch gotchas
+`<name>.env.local` is optional and may contain only non-secret machine data:
 
-1. **Flag conflict.** `mosaic yolo claude` already injects `--dangerously-skip-permissions`. Do
+- `MOSAIC_RUNTIME_BIN`
-   **not** also pass `--permission-mode bypassPermissions` — the `claude` binary would receive both.
+- `MOSAIC_HEARTBEAT_RUN_DIR`
-   Use `mosaic yolo claude …` alone (yolo covers the unattended posture), **or** non-yolo
+- `MOSAIC_HEARTBEAT_INTERVAL`
-   `mosaic claude --permission-mode bypassPermissions …`. Never mix the two.
+- `MOSAIC_CLAUDE_JSON`
-2. **`MOSAIC_AGENT_NAME` must reach the pane.** The launcher bakes it from the instance name, and
+- `CLAUDE_CONFIG_DIR`
-   `composeContract` gates the Fleet-Comms block on it (`launch.ts`, in `composeContract`) — **and**
-   the role must be a member of `roster.yaml`, or the block resolves empty.
-3. **`launchRuntime` guards.** `mosaic yolo claude` runs `checkSoul` / `checkRuntime` /
-   `checkSequentialThinking`. The host needs `SOUL.md` and the sequential-thinking MCP, or the
-   launch aborts (a raw `claude` invocation skipped these checks). Dry-run the composed command in a
-   throwaway tmux session before swapping a live launcher.
 
-## Why per-agent `.env` survives upgrades (#632)
+Paths must be safe absolute paths and the heartbeat interval must be a positive integer. Projection,
+local, and quarantine files must be private regular files; the managed directories must be real,
+private, non-symlink paths. Violations fail closed before tmux interaction.
 
-`install.sh` `PRESERVE_PATHS` includes `fleet/*.yaml`, `fleet/agents`, and `fleet/run`, so
+## Legacy input and diagnostics
-`mosaic update`'s framework re-seed **preserves** your roster and per-agent `.env` overrides
-(glob-aware `cp` fallback; matching TS parity in `file-adapter.ts`). Before #632, an auto re-seed
-could wipe them — which is exactly why PATH A's `.env` override is safe to rely on now.
 
-## Inspecting the comms wiring
+A legacy `<name>.env` is input only during projection generation. Roster-owned keys are regenerated;
+valid allowed local data can move to `.env.local`; invalid legacy input is privately retained at
+`<name>.env.quarantine`. Neither legacy nor quarantine files are launch authority.
 
-- `mosaic fleet comms-block <role>` prints the Fleet-Comms cheat-sheet a given role receives at
+Diagnostics expose only rule code, key name, and a SHA-256 content hash. They do not reveal command
-  launch — its `[host:session]` identity, the exact `agent-send.sh` command for each peer, and the
+text, credentials, or other values.
-  FLIP / `--verify` conventions. `--host <h>` previews a cross-host view. An unknown role or missing
-  roster **fails loud** (stderr + non-zero exit), so a typo is never a silent no-op.
-- Versus `mosaic compose-contract <runtime>`: that emits the **whole** system prompt and reads the
-  role from `MOSAIC_AGENT_NAME` (a full-prompt smoke test). `comms-block` is the targeted,
-  explicit-arg, comms-only view — e.g. `mosaic fleet comms-block coder0-0` to preview a peer.
 
-## North Star / future direction
+## Launch and stop behavior
 
-**Vision:** a webUI lets the user edit each agent's launch config — switch **harness**
+The launcher obtains the agent's socket only from the validated generated projection. It creates or
-(claude / pi / codex / opencode), toggle **yolo**, pick a **model**, set a **command/channels**
+checks the exact `=<agent-name>` tmux target; it never uses an ambient socket or fuzzy session match.
-override — with no terminal.
+The same strict parser runs before exact-stop behavior. A fresh native Pi heartbeat remains authoritative;
+the shell sidecar only provides fallback state when the native marker is stale or absent.
 
-**Continuity — this is not a new launch path.** It is a data-model + UI-binding layer over the
+`mosaic fleet comms-block <role>` can inspect the role's resolved Fleet-Comms block. It is a read-only
-existing roster-driven launcher. Field-by-field status today:
+inspection tool and fails loudly for an unknown role or missing roster.
 
-| Launch-config field      | Roster-native today? | Mechanism / gap                                                                                                                                          |
+## Current M2 boundary
-| ------------------------ | -------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------- |
-| **harness** (`runtime`)  | ✅ end-to-end        | `roster.runtime` → `generateAgentEnv` emits `MOSAIC_AGENT_RUNTIME` → launcher line 44. UI just writes the field.                                         |
-| **model** (`model_hint`) | ✅ end-to-end        | `roster.model_hint` → `MOSAIC_AGENT_MODEL` → launcher line 44 `--model`. UI just writes the field.                                                       |
-| **yolo**                 | ❌ new               | Launcher line 44 **hardcodes** `mosaic yolo`. A non-yolo toggle needs a roster `yolo` field → emit `MOSAIC_AGENT_YOLO` → make line 44 conditional.       |
-| **command / channels**   | ❌ new               | `MOSAIC_AGENT_COMMAND` is **consumed** (launcher line ~12) but `generateAgentEnv` does not emit it. Needs a roster `command`/`channels` field → emitted. |
 
-**The arc:**
+FCM-M2-001 supplies generated/local parsing, validation, projection, quarantine, and launch-boundary
-
+evidence only. It does not authorize roster CRUD expansion, reconciliation, lifecycle changes, remote
-- **A** — `.env` `MOSAIC_AGENT_COMMAND` hatch: manual, ships now, kept safe across upgrades by #632.
+or connector mutation, site canaries, or migration. M3 must establish the local reconcile/lifecycle
-- **B** — roster-native launch-config: harness + model are already there; add the **yolo** toggle
+path; M4 separately provides migration preview, canary, and rollback gates.
-  (line-44 conditional) and **command/channels** emission to complete the data model.
-- **webUI** — binds dropdowns/toggles directly to those four roster fields.
-
-PATH A's `.env` override is the **manual form** of exactly what PATH B makes roster-native and the
-webUI edits — one continuous arc, not three separate features. PATH B is tracked as #636.

docs/fleet/LEGACY-EXAMPLE-PROFILE-DISPOSITION-INVENTORY.md

@@ -7,7 +7,8 @@ The v2 compiler may not silently accept an unresolved class. Before M1 exits, ev
 below must be either migrated and executable, retained as an explicitly versioned v1 fixture, or
 retired with a replacement/deprecation note. Class resolution must use the existing
 profile/persona/provision baseline-plus-`roles.local` resolver; this inventory does not create a
-parallel resolver.
+parallel resolver. The current executable implementation and per-artifact outcomes are recorded in
+[the disposition evidence](./migration/example-profile-disposition.md).
 
 ## Examples
 

docs/fleet/how-to/customize-roles.md

@@ -0,0 +1,54 @@
+# Customize Fleet Roles
+
+Mosaic resolves persona contracts through two layers:
+
+1. `fleet/roles/<canonical-class>.md` — seeded baseline contract.
+2. `fleet/roles.local/<canonical-class>.md` — operator override or custom role; this layer wins.
+
+The same shared resolver is used by profile validation, provisioning, roster-v2 semantic validation,
+and launch-time persona injection.
+
+## Override a baseline role
+
+Create a readable Markdown contract under `roles.local` with the canonical filename and class marker:
+
+```markdown
+# Code — local role definition
+
+The local code role (`class: code`) follows the operator's repository conventions.
+```
+
+Save it as `fleet/roles.local/code.md`. Do not edit generated or seeded baseline assets when the goal
+is a durable local customization.
+
+Legacy aliases canonicalize before lookup. Therefore `roles.local/implementer.md` does not override
+`code`; use `roles.local/code.md`. See [Legacy Fleet Class Aliases](../migration/legacy-class-aliases.md).
+
+## Add a custom class
+
+A custom class remains supported when a readable contract exists for the exact identifier:
+
+```markdown
+# Release notes — local role definition
+
+The release-notes role (`class: release-notes`) prepares operator-reviewed release copy.
+```
+
+Save it as `fleet/roles.local/release-notes.md`, then reference `class: release-notes` and a matching
+`tool_policy: release-notes` in roster v2. Adding only a `LIBRARY.md` row is insufficient.
+
+Names such as `worker`, `analyst`, and `canary` are not built-in aliases; they need genuine custom
+contracts. `agents[].alias`, Tess, and Ultron are display names and cannot select a class.
+
+## Validation and authority boundaries
+
+Semantic validation reads the winning contract and rejects missing, unreadable, or empty files.
+Protected authority is derived from canonical class metadata in code, never from role prose. A custom
+contract cannot claim merge, validation-certificate, orchestration, lease, or interaction authority.
+
+Roster v2 also fails closed when a protected class and tool policy do not match after canonicalization,
+or when an unprotected class claims a protected tool policy. The legacy `operator-interaction` policy
+canonicalizes to `interaction`.
+
+Role customization does not issue leases, store validation certificates, mutate credentials, or
+change lifecycle state.

docs/fleet/migration/example-profile-disposition.md

@@ -0,0 +1,52 @@
+# Executable Fleet Example, Profile, and Service-Preset Dispositions
+
+**Issue:** #758 · **Card:** FCM-M1-003 · **Status:** M1 executable disposition evidence
+
+This document records the executable disposition for every currently shipped fleet YAML artifact.
+The authoritative baseline classification remains the
+[legacy inventory](../LEGACY-EXAMPLE-PROFILE-DISPOSITION-INVENTORY.md). The executable guard is
+`packages/mosaic/src/fleet/example-profile-dispositions.ts`; its test fails if a shipped YAML
+artifact is added, removed, or left without one of the dispositions below.
+
+## Disposition rules
+
+- **Explicit v1 fixture:** the artifact is loaded through the existing v1 roster parser and must
+  declare `version: 1`. It remains a compatibility fixture; it is not silently treated as a v2
+  roster or given inferred aliases.
+- **Canonical profile:** the artifact is loaded through `loadProfiles`, which uses the shared
+  baseline-plus-`roles.local` persona resolver and rejects unreadable or unresolved classes.
+- **Canonical service policy:** the artifact is loaded through the operator-interaction service
+  policy reader and provisioned with a generic supplied identity. It validates its runtime, model,
+  reasoning, and legacy tool-policy compatibility without hardcoding a product identity.
+
+No artifact is retired in this card. A later retirement requires both a replacement link and a
+visible deprecation note; the executable guard must then record the new disposition before the
+artifact can be removed.
+
+## Shipped artifacts
+
+| Artifact                             | Disposition              | Executable path                   | Compatibility notes                                                                              |
+| ------------------------------------ | ------------------------ | --------------------------------- | ------------------------------------------------------------------------------------------------ |
+| `examples/coding.yaml`               | Explicit v1 fixture      | v1 roster parser                  | Retains approved `implementer` and `reviewer` compatibility inputs.                              |
+| `examples/general.yaml`              | Explicit v1 fixture      | v1 roster parser                  | Retains unresolved `worker` without an inferred canonical role.                                  |
+| `examples/hybrid.yaml`               | Explicit v1 fixture      | v1 roster parser                  | Retains `implementer`, `reviewer`, and resolver-dependent `researcher`.                          |
+| `examples/local-canary.yaml`         | Explicit v1 fixture      | v1 roster parser                  | Retains the local-tmux canary topology.                                                          |
+| `examples/minimal.yaml`              | Explicit v1 fixture      | v1 roster parser                  | Retains `canary` without an inferred canonical role.                                             |
+| `examples/operator-interaction.yaml` | Explicit v1 fixture      | v1 roster parser                  | Keeps Tess only as an example instance name; `operator-interaction` remains compatibility input. |
+| `examples/research.yaml`             | Explicit v1 fixture      | v1 roster parser                  | Retains resolver-dependent `researcher` and `analyst`.                                           |
+| `profiles/business.yaml`             | Canonical profile        | shared profile/persona resolver   | Every referenced business class must resolve to a readable contract.                             |
+| `profiles/marketing.yaml`            | Canonical profile        | shared profile/persona resolver   | Every referenced marketing class must resolve to a readable contract.                            |
+| `profiles/personal-assistant.yaml`   | Canonical profile        | shared profile/persona resolver   | No interaction equivalence is inferred.                                                          |
+| `profiles/research.yaml`             | Canonical profile        | shared profile/persona resolver   | Every research class must resolve to a readable contract.                                        |
+| `profiles/software-delivery.yaml`    | Canonical profile        | shared profile/persona resolver   | Retains the governance profile; authority validation remains FCM-M1-002 evidence.                |
+| `services/operator-interaction.yaml` | Canonical service policy | service-policy reader/provisioner | Generic provisioning supplies the instance name; the policy itself never names Tess.             |
+
+## Running the guard
+
+```bash
+pnpm --filter @mosaicstack/mosaic test -- example-profile-dispositions.spec.ts
+```
+
+The guard is intentionally limited to shipped assets and validation. It does not generate
+environment files, mutate a roster, reconcile a fleet, migrate an installed roster, or launch an
+agent.

docs/fleet/migration/legacy-class-aliases.md

@@ -0,0 +1,40 @@
+# Legacy Fleet Class Aliases
+
+Fleet class compatibility is intentionally narrow. The shared resolver accepts exactly three legacy
+class names and converts them to canonical classes before persona lookup:
+
+| Legacy value           | Canonical value | Migration action                                                                                                       |
+| ---------------------- | --------------- | ---------------------------------------------------------------------------------------------------------------------- |
+| `implementer`          | `code`          | Replace class and tool-policy references with `code`.                                                                  |
+| `reviewer`             | `review`        | Replace class and tool-policy references with `review`.                                                                |
+| `operator-interaction` | `interaction`   | Replace class and roster-v2 tool-policy references with `interaction`. The legacy service artifact remains compatible. |
+
+Alias support preserves existing inputs while provisioning and typed semantic output use canonical
+identities. Requested and canonical class values remain separately observable during semantic
+validation.
+
+## Lookup and override behavior
+
+Canonicalization precedes baseline and `roles.local` lookup. A legacy-named override such as
+`roles.local/implementer.md` is not a separate authority and is not selected for an `implementer`
+request. Customize the canonical role instead, for example `roles.local/code.md`.
+
+The compatibility file `operator-interaction.md` remains shipped, but `interaction` is the canonical
+role class. Tess is an example display name only.
+
+## Unresolved and custom classes
+
+No names are inferred from historical usage, instance names, or similar wording. `worker`, `analyst`,
+`canary`, Tess, and Ultron are not aliases. An otherwise unknown class is accepted only if the shared
+resolver can read an actual baseline or `roles.local` contract for that exact class. A `LIBRARY.md`
+row without a readable contract fails semantic validation.
+
+Custom classes receive no protected authority implicitly. Protected class/tool-policy mismatches
+fail closed.
+
+## Retirement guidance
+
+New configuration should emit canonical values. Existing inputs may use the three aliases during the
+compatibility period, but operators should migrate class and tool-policy fields together. Do not
+create new legacy-named role overrides; move their intended content to the canonical filename and
+validate the roster/profile before removing the old artifact.

docs/fleet/reference/generated-env-boundary.md

@@ -0,0 +1,96 @@
+# Fleet Generated Environment Boundary
+
+**Card:** FCM-M2-001 · **Issue:** #758 · **Status:** unreleased/card-local
+
+The local fleet roster is the desired-state authority. A launch reads a deterministic,
+roster-derived generated projection and an optional strictly data-only local file; neither file is
+a second roster or a command configuration surface.
+
+## Paths and ownership
+
+For agent `<name>` under `<MOSAIC_HOME>/fleet/agents/`:
+
+| Path                    | Owner                    | Purpose                                                                                                                      |
+| ----------------------- | ------------------------ | ---------------------------------------------------------------------------------------------------------------------------- |
+| `<name>.env.generated`  | Mosaic projection writer | Complete deterministic launch data rendered from the authoritative roster.                                                   |
+| `<name>.env.local`      | Operator                 | Optional, constrained local machine data. It cannot shadow generated keys.                                                   |
+| `<name>.env`            | Legacy input only        | Read once during projection generation, then regenerated/relocated or privately quarantined. It is never a launch authority. |
+| `<name>.env.quarantine` | Mosaic quarantine        | Mode-`0600` private record of forbidden legacy input; it is never read by the launcher.                                      |
+
+The systemd templates do not load either environment file. They invoke Bash with a fixed, cleared
+bootstrap environment; the launcher reads and validates `.env.generated` and `.env.local` itself before
+it queries, creates, or stops an exact tmux session. It does not `source`, `eval`, or execute an
+environment-supplied command. Exact stop derives its socket from the same validated generated projection,
+not from systemd or ambient environment data.
+
+All projection, local, and quarantine files must be regular files with no group or world permissions.
+The agent environment directory must also be a real, non-symlink private directory; it is validated
+before either environment file is read or tmux is queried. Unsafe paths, symlinks, or permissions fail
+closed. Diagnostics identify only a rule code, key name, and SHA-256 content hash; they never print
+values, credential material, or command text.
+
+## Allowed data
+
+`.env.generated` is complete and ordered exactly as follows:
+
+```dotenv
+MOSAIC_AGENT_NAME=<roster name>
+MOSAIC_AGENT_CLASS=<roster class>
+MOSAIC_AGENT_RUNTIME=<roster runtime>
+MOSAIC_AGENT_MODEL=<roster model hint>
+MOSAIC_AGENT_REASONING=<roster reasoning>
+MOSAIC_AGENT_TOOL_POLICY=<roster tool policy>
+MOSAIC_AGENT_WORKDIR=<absolute roster work directory>
+MOSAIC_TMUX_SOCKET=<roster socket or empty>
+```
+
+The generated launch contract supports only `claude`, `codex`, `opencode`, and `pi`. `fleet add`
+uses that same runtime authority and rejects any other runtime before it writes the roster or changes
+projection, local, or quarantine files. The legacy dogfood stub on its separate `mosaic-factory`
+socket remains an observability canary; it has no generated-launch adapter and cannot be added through
+this projection path.
+
+`.env.local` may contain only these non-secret data keys:
+
+- `MOSAIC_RUNTIME_BIN`
+- `MOSAIC_HEARTBEAT_RUN_DIR`
+- `MOSAIC_HEARTBEAT_INTERVAL`
+- `MOSAIC_CLAUDE_JSON`
+- `CLAUDE_CONFIG_DIR`
+
+Local paths must be safe absolute paths and the interval must be a positive integer. Comments,
+quoted/export syntax, duplicate keys, unknown keys, generated-key shadowing, sensitive key names,
+and `MOSAIC_AGENT_COMMAND` are rejected. The launcher derives the only executable command from the
+validated runtime, model, and reasoning data; no arbitrary command compatibility path exists. When a
+Pi runtime writes a fresh `<name>.hb.native` marker, its native heartbeat remains authoritative; the
+shell sidecar resumes its `status=ok` fallback only after that marker is stale or absent.
+
+## Legacy disposition
+
+During projection generation, legacy roster-derived keys are regenerated from the roster. A valid
+allowed local value is relocated to `.env.local`; forbidden, malformed, duplicate, sensitive, and
+unknown legacy entries cause the legacy file to be moved to `.env.quarantine` and are represented by
+sanitized diagnostics. This is deterministic and idempotent after the legacy file has been consumed.
+
+## USC interface packet
+
+This card does not add a USC site file, write a USC roster, or run a site canary. The following is the
+consolidated downstream interface packet. Status is deliberately separated from checkout presence: no
+product release version has been evidenced for this interface set.
+
+| Interface               | Canonical public path and version                                                                                                                 | Tracker/release status                                                                                                | Downstream limit                                                                              |
+| ----------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------- |
+| M1 structural compiler  | `parseRosterV2` in `packages/mosaic/src/fleet/roster-v2.ts`; schema `docs/fleet/reference/roster-v2.schema.json`; roster `version: 2`             | FCM-M1-001 is recorded done, merged as #764 (`aa5b43b`); no released product version is asserted here.                | Parse YAML/JSON and canonicalize a supplied v2 site roster without writes.                    |
+| M1 semantic resolver    | `validateRosterV2Semantics` in `packages/mosaic/src/fleet/roster-v2.ts`; baseline `framework/fleet/roles/` plus `roles.local/`                    | FCM-M1-002 remains `in-progress` in `docs/TASKS.md`; unreleased.                                                      | Reuse the shared resolver only; no parallel role resolver or lifecycle action.                |
+| M1 disposition evidence | `packages/mosaic/src/fleet/example-profile-dispositions.ts`; `docs/fleet/migration/example-profile-disposition.md`; retained fixture `version: 1` | FCM-M1-003 remains `not-started` in `docs/TASKS.md`; unreleased even though these checkout artifacts are inspectable. | Inspect fixture/profile/service disposition evidence only; it is not migration authorization. |
+| M2 generated boundary   | `packages/mosaic/src/fleet/generated-env-boundary.ts`; generated projection contract in this document                                             | FCM-M2-001 card-local and uncommitted; unreleased.                                                                    | Render/write a roster-derived projection; local input is never authority.                     |
+
+The canonical source remains `<MOSAIC_HOME>/fleet/roster.yaml` for the current local fleet path.
+Generated environment data is a rebuildable projection, not an operator-editable source of membership,
+runtime policy, or lifecycle state.
+
+**Corrected downstream gates:** M2 supplies only parse/validation/projection evidence and does not
+permit a USC site canary, reconciliation, or lifecycle mutation. M3 must first define and validate the
+canonical local reconcile/lifecycle path. M4 then supplies preview/migration and its separate
+canary/rollback gates; only after those M3 and M4 gates may a site migration or canary be considered.
+This card authorizes none of those actions.

docs/fleet/reference/role-classes.md

@@ -0,0 +1,45 @@
+# Fleet Role Classes and Authority
+
+A fleet role class is a machine identity resolved from the persona library. Resolution uses the
+canonical class before consulting the baseline `fleet/roles/` and operator `fleet/roles.local/`
+layers. A readable role contract is required; an index entry alone is not semantic success.
+
+## Canonicalization
+
+Only these legacy class aliases are recognized:
+
+| Requested class        | Canonical class |
+| ---------------------- | --------------- |
+| `implementer`          | `code`          |
+| `reviewer`             | `review`        |
+| `operator-interaction` | `interaction`   |
+
+No other alias is inferred. In particular, `worker`, `analyst`, and `canary` are custom classes only
+when an operator supplies a readable contract for that exact class. Tess and Ultron are instance
+names, not classes. `agents[].alias` is display-only and cannot grant authority.
+
+Canonicalization happens before role lookup. For example, requesting `implementer` resolves
+`code.md`; a separate `roles.local/implementer.md` cannot redefine the legacy alias. A canonical
+`roles.local/code.md` still overrides the baseline `roles/code.md` contract.
+
+## Protected authority
+
+Protected authority is immutable metadata derived only from canonical class. Role prose, instance
+name, display alias, tool policy, runtime, and custom role files cannot grant it.
+
+| Canonical class   | Granted authority                                  | Explicit limits                                                                   |
+| ----------------- | -------------------------------------------------- | --------------------------------------------------------------------------------- |
+| `merge-gate`      | Sole approve-to-land and merge authority           | No authority is inferred by similarly named custom roles or policies.             |
+| `validator`       | May issue a validation certificate                 | Cannot approve-to-land or merge.                                                  |
+| `orchestrator`    | May orchestrate, manage topology, and issue leases | Cannot approve-to-land or merge.                                                  |
+| `team-leader`     | May use orchestrator-leased capacity               | Cannot issue leases or mutate roster, configuration, credentials, or merge state. |
+| `interaction`     | Request and status surface                         | Cannot orchestrate, issue leases, mutate roster/configuration, or merge.          |
+| all other classes | No protected authority implicitly                  | Custom contracts do not acquire protected powers from prose.                      |
+
+Roster-v2 semantic validation requires a protected class and its canonical tool policy to match. It
+also rejects an unprotected class paired with a protected tool policy. The legacy tool-policy name
+`operator-interaction` canonicalizes to `interaction`.
+
+This mapping describes authority metadata only. Lease issuance, validation-certificate storage or
+workflow, lifecycle reconciliation, credentials, roster mutation, and merge execution are outside
+this resolver contract.

docs/fleet/reference/roster-v2-fields.md

@@ -81,6 +81,35 @@ agents:
 | `agents[].lifecycle.desired_state`                   | yes      | `running` or `stopped`                                                                               |
 | `agents[].launch.yolo`                               | yes      | boolean; structured data only, not an arbitrary command escape hatch                                 |
 
+## Semantic handoff
+
+`parseRosterV2` and `normalizeRosterV2` remain synchronous and structural. After structural success,
+call the asynchronous `validateRosterV2Semantics` handoff before using persona identity or authority.
+That validator batches the baseline `fleet/roles/` and operator `fleet/roles.local/` scans, then
+delegates every agent to the shared persona resolver.
+
+Semantic validation:
+
+- requires the winning role contract to be readable and non-empty; `LIBRARY.md` membership alone does
+  not resolve a class;
+- retains `requestedClass` separately from `canonicalClass` in typed output;
+- canonicalizes only `implementer` to `code`, `reviewer` to `review`, and
+  `operator-interaction` to `interaction`;
+- canonicalizes `tool_policy` with the same exact alias table;
+- rejects protected class/tool-policy mismatches in either direction, while accepting
+  `class: operator-interaction` with `tool_policy: operator-interaction` as canonical
+  `interaction`;
+- derives immutable protected authority only from canonical class; and
+- accepts custom baseline or `roles.local` classes without granting protected authority.
+
+`agents[].alias` remains display-only. Tess and Ultron are instance names, never semantic classes.
+Canonicalization happens before role-layer lookup, so a legacy-named override cannot redefine an
+alias as separate authority. See [Role Classes and Authority](./role-classes.md) and
+[Customize Fleet Roles](../how-to/customize-roles.md).
+
+This handoff performs no filesystem, systemd, tmux, roster, credential, lease, certificate, or
+lifecycle mutation.
+
 ## Fail-closed boundary
 
 Every object is `additionalProperties: false`. The compiler rejects unknown, missing, malformed,

docs/scratchpads/758-fcm-m1-002-shared-role-resolution.md

@@ -0,0 +1,148 @@
+# FCM-M1-002 — Shared role resolution
+
+- **Task:** `FCM-M1-002`
+- **Issue:** `mosaicstack/stack#758`
+- **Branch:** `feat/758-shared-role-resolution`
+- **Starting head:** `32e75c67b094de443d37fe7d5ff8d25cdfc8b39d`
+- **Role:** implementation worker; independent review and merge remain outside this worker
+
+## Objective
+
+Reuse the existing baseline-plus-`roles.local` persona resolver as the sole class authority for roster-v2 semantics, profile validation, provisioning, and launch/persona resolution. Add exact approved alias canonicalization, fail-closed semantic validation, immutable canonical-class authority contracts, required baseline roles, and operator documentation without implementing lifecycle, mutation, credentials, certificate workflow, or later FCM cards.
+
+## Budget
+
+- Soft budget: **25K tokens**.
+- Strategy: inspect once, implement in small TDD units, run focused suites before the full package gate, and avoid unrelated refactors or M1-003/M2/M4 scope.
+
+## Plan
+
+1. Map the existing persona resolver, roster-v2 compiler, profile/provision consumers, launch resolution, role library, and focused tests.
+2. Write denial/invariant tests first for aliases, canonicalization-before-override, unreadable roles, authority boundaries, policy mismatch, canonical provision output, and resolver parity.
+3. Run the focused suites and record the expected red evidence.
+4. Implement one shared canonical resolution and authority contract in/through `fleet-personas.ts`; delegate roster semantic validation and profile/provision paths to it.
+5. Add baseline `validator`, `team-leader`, and `interaction` role contracts plus `LIBRARY.md` entries while retaining `operator-interaction` compatibility.
+6. Add the required role reference, alias migration, customization guide, and roster-v2 semantic handoff documentation.
+7. Run focused tests, the full `@mosaicstack/mosaic` suite, typecheck, lint, Prettier, `git diff --check`, situational verification, independent code/security review, and remediation.
+8. Commit with the required co-author trailer, run the CI queue guard, push the existing branch, and create/update exactly one PR to `main` with `Refs #758`.
+
+## TDD evidence
+
+### Red
+
+After installing worktree-local dependencies and building `@mosaicstack/db`, the pre-implementation
+focused run collected the intended tests and failed as expected:
+
+```text
+2 test files failed; 32 tests failed; 32 tests passed
+```
+
+Expected failures named the missing `canonicalizeRoleClass`,
+`authorityForCanonicalClass`, and `validateRosterV2Semantics` APIs, absent requested/canonical typed
+output, and unresolved required canonical role contracts. An earlier run that failed before test
+collection on an unresolved `yaml` dependency was treated as environment setup, not TDD evidence.
+
+### Green
+
+Focused role-resolution and affected service fixtures:
+
+```text
+6 test files passed; 109 tests passed
+```
+
+The focused set covers personas, profiles, provision, launch persona contract, roster-v2 semantics,
+and the operator-interaction service fixture. The final profile tests also cover readable lead/floor
+compatibility and canonical collision denial.
+
+## Tests and gates
+
+- Focused suites: pass, **6 files / 109 tests**.
+- Full `@mosaicstack/mosaic` suite: pass, **50 files / 713 tests**. Workspace package build outputs
+  were prepared first because a clean worktree has no dependency `dist` entries.
+- `pnpm --filter @mosaicstack/mosaic typecheck`: pass.
+- `pnpm --filter @mosaicstack/mosaic lint`: pass.
+- Prettier check over every changed file: pass.
+- `git diff --check`: pass.
+- Runtime/file-boundary evidence: real role library, profile/provision filesystem integration,
+  launch-time synchronous contract injection, v1 roster parser round-trip, roster-v2 semantic
+  filesystem checks, and operator-interaction service fixtures all pass without live mutation.
+- Independent code review: **APPROVE**, no blocking or non-blocking findings; reviewed complete
+  tracked/untracked delta including the canonical collision guard. Residual: roster-v2 semantic
+  validation is an explicit async handoff with production caller wiring owned by later work.
+- Independent security review: **APPROVE**, no verified authority/security findings on the final
+  delta.
+
+### Post-PR fail-closed remediation
+
+Independent rereview found resolver fail-open edges that the original green PR head did not cover. The
+remediation remained uncommitted until every finding was reproduced red-first and the same reviewer
+approved the complete two-file delta.
+
+Final regression evidence:
+
+```text
+persona resolver: 47/47
+focused affected suites: 6 files / 138 tests
+root-container resolver suites: 86/86
+full canonical run: 42/42 Turbo tasks; Mosaic 50 files / 733 tests
+```
+
+DB migration, typecheck, lint, Prettier, and `git diff --check` also passed. Coverage now proves:
+
+- unreadable, unscannable, direct-dangling, ancestor-dangling, and literal `..` traversal override paths
+  fail closed across async, sync, listing, and status APIs;
+- genuinely missing override directories still permit baseline fallback;
+- cached missing scans are revalidated before fallback;
+- marker-defined identity and domain metadata are revalidated on the second read;
+- `LIBRARY.md` rows and incidental later markers cannot define, shadow, or advertise personas.
+
+Exact-head pipeline `1819` passed for rebased head `4d990eee…`, but the independent reviewer-of-record
+returned **REQUEST CHANGES** after reproducing three additional edge failures: a canonical filename could
+inherit protected authority despite a conflicting explicit first marker, cached `scanned` absence could
+miss an override created before baseline fallback, and inherited plain-object names such as `constructor`
+could corrupt alias/authority lookup. Merge remained held.
+
+Each failure was reproduced red-first in the persona suite (4 failing assertions), then remediated without
+expanding card scope. Explicit first markers now own identity and filename fallback applies only to
+markerless contracts; every second read rejects a newly introduced conflicting marker regardless of
+cached classification; cached async resolution re-scans the override layer immediately before every
+baseline fallback; alias and authority registries require own-property matches. Current uncommitted
+evidence is persona **52/52**, focused affected suites **6 files / 143 tests**, and full Mosaic package
+**50 files / 738 tests**, plus typecheck, lint, Prettier, and `git diff --check`. Independent
+finding-specific rereview **APPROVED** the complete uncommitted three-file remediation after direct
+adversarial reproduction of all three findings and the follow-up markerless TOCTOU. All post-commit
+exact-head gates remain required.
+
+## Risks and boundaries
+
+- **Security-sensitive authority:** authority must derive only from canonical class, never role prose, aliases, display names, or tool-policy text.
+- **Resolver divergence:** no second regex, registry, scanner, or prose parser may be introduced.
+- **Alias capture:** aliases must canonicalize before baseline/`roles.local` lookup so local files cannot redefine legacy aliases as separate authority.
+- **Readable persona requirement:** semantic success requires a resolved readable persona, not class-set membership.
+- **Scope control:** no roster mutation, lifecycle, lease issuance, certificate workflow/storage, credentials, remote reconciliation, provision-v2 conversion, or shipped-example disposition execution.
+- **Coordination:** `docs/TASKS.md` is read-only and remains orchestrator-owned.
+
+## Acceptance-evidence mapping
+
+| Requirement / criterion | Verification evidence |
+| --- | --- |
+| `FCM-REQ-02` shared semantic resolver | Async/sync resolver parity; roster-v2 delegates batched scans and resolution; profiles/provision and launch reuse `fleet-personas.ts`; no second scanner or class-marker regex added. |
+| `FCM-REQ-07` canonical classes and authority boundaries | Exact alias and non-alias tests; immutable authority invariant tests; all required canonical contracts resolve through the real role library. |
+| `AC-FCM-01` structural + semantic roster validation | Synchronous parser/normalizer tests remain intact; async semantic tests cover aliases, custom roles, unreadable/unresolved roles, `LIBRARY`-only rejection, and bidirectional protected policy mismatch. |
+| `AC-FCM-07` protected authority invariants | Denial tests prove merge-gate-only merge, validator certificate-only, orchestrator/team-leader/interaction limits, no implicit custom-role authority, and canonical tool-policy matching. |
+
+## Documentation
+
+- `docs/fleet/reference/role-classes.md`
+- `docs/fleet/migration/legacy-class-aliases.md`
+- `docs/fleet/how-to/customize-roles.md`
+- `docs/fleet/reference/roster-v2-fields.md` semantic handoff
+- Baseline role contracts and `LIBRARY.md` rows for `validator`, `team-leader`, and `interaction`
+
+## Residual risks
+
+- Provisioning remains intentionally v1 and does not emit `reports_to`; canonical topology is retained
+  in its typed seat/summary path only, matching the existing v1 parser boundary.
+- Alias support remains for compatibility; new configuration should emit canonical identities.
+- This card defines authority metadata and validation only. Enforcement workflows for leases,
+  certificates, lifecycle, and mutation remain owned by later FCM cards.

docs/scratchpads/758-fcm-m1-003-example-profile-dispositions.md

@@ -0,0 +1,37 @@
+# FCM-M1-003 — Executable example/profile/service-preset dispositions
+
+- **Task / issue:** FCM-M1-003 / #758
+- **Branch / base:** `test/758-example-profile-dispositions` from `origin/main` `a5e8e554012f27898e035d2882a8e47e1a02fe97`
+- **Objective:** Make every artifact in the M0 legacy disposition inventory executable evidence: it must validate canonically, be explicitly retained as a v1 fixture, or be retired with a replacement/deprecation link.
+- **Scope:** Validation and explicit version/retirement metadata only for shipped examples, profiles, and the operator-interaction service preset. Reuse the central resolver and existing v2 roster compiler.
+- **Out of scope:** Generated environment boundaries, CRUD, reconciliation/apply, migration, live fleet mutation, and `docs/TASKS.md`.
+- **Budget:** 20K card allocation; use focused package tests before full package validation.
+
+## Plan
+
+1. Inventory exact shipped artifacts and existing compiler/resolver/profile tests.
+2. Add failing behavior tests covering all listed artifacts and their documented disposition.
+3. Implement minimal declarative fixture/disposition validation; do not add a role/class resolver.
+4. Run focused and package quality gates; obtain independent code and security review.
+5. Commit, queue-guard, push, open one `main` PR with `Refs #758`.
+
+## Progress
+
+- Intake complete: verified no branch, worktree, or open PR for this card before creating this isolated worktree.
+- Requirements read: FCM PRD, FCM-M1-003 task row, M0 disposition inventory, delivery/QA/documentation guides.
+- TDD: RED recorded with `pnpm --filter @mosaicstack/mosaic test -- example-profile-dispositions.spec.ts` failing because the new module did not exist; GREEN recorded after the minimal guard implementation. The focused suite now has 4 passing tests, including undeclared-artifact and missing-explicit-v1-version denials.
+- Independent review: initial code review found the service policy path was hardcoded; remediation iterates declared `canonical-service-policy` artifacts. Exact-head code review approved and exact-head security review found no issues.
+
+## Risks / decisions
+
+- The M0 inventory permits unresolved legacy roles only when explicitly v1-versioned or retired. Do not infer aliases beyond the three approved by FCM-M1-002.
+- `docs/TASKS.md` is orchestrator-owned and will not be edited.
+
+## Verification evidence
+
+- Focused TDD guard: `pnpm --filter @mosaicstack/mosaic test -- example-profile-dispositions.spec.ts` — PASS (4 tests).
+- Full package suite: `pnpm --filter @mosaicstack/mosaic test` — PASS (51 files, 742 tests).
+- Static gates: `pnpm --filter @mosaicstack/mosaic typecheck`, `pnpm --filter @mosaicstack/mosaic lint`, and `pnpm format:check` — PASS.
+- Diff gate: `git diff --check` — PASS.
+- Exact-head reviews: `codex-code-review.sh --uncommitted` — APPROVE; `codex-security-review.sh --uncommitted` — no findings.
+- Delivery: committed as `9a9ad1a`, pushed after `ci-queue-wait.sh --purpose push`, and opened PR [#770](https://git.mosaicstack.dev/mosaicstack/stack/pulls/770) to `main` with `Refs #758`. `pr-ci-wait.sh -n 770` reported terminal-green Woodpecker pipeline [#1823](https://ci.mosaicstack.dev/repos/47/pipeline/1823/1).

docs/scratchpads/fcm-m2-001-generated-env-boundary.md

@@ -0,0 +1,110 @@
+# FCM-M2-001 — Generated Environment Boundary
+
+- **Issue/card:** #758 / FCM-M2-001
+- **Branch/base:** `feat/758-generated-env-boundary` from `origin/main` `e9c4aa3e8b3780719cd5a43c0ef3f37fc70de666`
+- **Budget assumption:** 30K-card budget; implement only the deterministic generated/local environment boundary and its launch-chain/docs/tests.
+
+## Objective
+
+Replace the generic fleet agent `.env` authority/merge path with a deterministic roster-derived `<agent>.env.generated` projection and strict, data-only `<agent>.env.local`. The roster remains the desired-state authority. Reject bad input before the launcher creates a tmux session; never print sensitive or privileged-command values.
+
+## Scope and non-goals
+
+- In scope: deterministic render/write, strict generated/local parse rules, legacy `.env` disposition/quarantine, systemd/launcher boundary, permission/path checks, focused fail-closed tests, operator/reference documentation, USC interface evidence.
+- Excluded: roster CRUD/mutation, v2 roster schema changes, lifecycle/reconcile/apply behavior, migration/canary rollout, connectors, remote surfaces, live-fleet actions, and M2-002.
+
+## Plan
+
+1. Add red tests for generated-key shadowing, malformed/duplicate/unknown/command/sensitive input, no-value diagnostics, deterministic/idempotent projection, secure file modes, and legacy disposition.
+2. Implement a pure strict environment contract plus atomic projection/quarantine helper.
+3. Replace the generic `.env` writer/merge path and systemd reference with `.env.generated` + `.env.local` ownership.
+4. Make the shell launcher parse the files without `source`/`eval`, reject unsafe input before tmux creation, and construct only the roster-derived runtime command.
+5. Add operator/reference documentation with the requested USC M1 interface evidence and M2–M4 gate statement.
+6. Run focused/package/root gates and audit the USC interface packet. Per continuation scope, stop before review, commit, push, PR, or live mutation.
+
+## Initial evidence
+
+- No existing owner: target worktree path absent; no target local/remote branch; `pr-list.sh -s open` returned no open PRs.
+- M1 compiler/API/docs and executable disposition evidence are present at the assigned base.
+- Existing launch chain writes `fleet/agents/<agent>.env`, preserves arbitrary legacy lines via `mergeAgentEnv`, sources `MOSAIC_AGENT_COMMAND`, and executes it through `bash -c`; all are M2 remediation targets.
+- `~/.config/mosaic/guides/SECURITY.md` is absent. Read the available security-review role contract and the vault/secrets guide instead.
+
+## Verification log
+
+### Continuation (2026-07-14)
+
+- Preserved the inherited 14-file delta; no reset, stash, rebase, roster mutation, lifecycle action,
+  live-fleet action, commit, push, or PR action was performed.
+- Focused gates passed:
+  - `pnpm --dir packages/mosaic test -- src/fleet/generated-env-boundary.spec.ts` — 1 file, 10 tests passed.
+  - `bash packages/mosaic/framework/tools/fleet/test-start-agent-session.sh` — passed.
+  - `bash packages/mosaic/framework/systemd/user/test-fleet-units.sh` — passed.
+  - `pnpm --dir packages/mosaic test -- src/commands/fleet.spec.ts` — 1 file, 192 tests passed.
+- Package gates passed before final documentation/format follow-up:
+  - `pnpm --dir packages/mosaic typecheck` — passed.
+  - `pnpm --dir packages/mosaic lint` — passed.
+  - `pnpm --dir packages/mosaic test` — 52 files, 752 tests passed.
+- `pnpm format:check` initially failed only for the new boundary reference and generated-boundary
+  TypeScript files; targeted Prettier normalization was applied. A final `pnpm format:check` passed.
+- USC packet audit: the M1 structural compiler is `parseRosterV2` with roster `version: 2`; the
+  semantic resolver is `validateRosterV2Semantics`; disposition artifacts retain `version: 1` fixture
+  evidence. `docs/TASKS.md` records M1-001 done, M1-002 in-progress, and M1-003 not-started; no
+  product release version is claimed. The packet now distinguishes these statuses from checkout
+  artifact presence and states the M2 → M3 → M4 downstream gates.
+
+## Review remediation (2026-07-14)
+
+- **Blocker 1 red-first:** Added a launcher reproducer with a `0777` `fleet/agents` parent and a private generated file. Before implementation, `bash packages/mosaic/framework/tools/fleet/test-start-agent-session.sh` failed: `FAIL: generated file under a world-writable parent was accepted`. The failure occurred after the launch path reached fake tmux, proving the parent was not validated.
+- **Blocker 2 red-first:** Added a `symlink()` projection-directory reproducer that preloads generated/local/quarantine/legacy target files and asserts no target mutation. Before implementation, `pnpm --dir packages/mosaic test -- src/fleet/generated-env-boundary.spec.ts` failed the new test because the existing writer followed the `agentEnvDir` symlink and parsed its target legacy input (`expected /unsafe-directory/i`, received `code=malformed-line`). The initial test-only missing `mkdir` import was corrected before recording this behavior failure.
+- **Blocker 3 red-first:** Added fresh/stale/absent native-heartbeat regression coverage. Before implementation, an isolated fake-tmux launcher reproducer with a fresh `<agent>.hb.native` marker failed `FAIL: fresh native heartbeat was overwritten`; the existing sidecar immediately replaced native `status=busy`/`model` content.
+- **Remediation result:** The launcher now rejects a group/world-accessible or symlinked `fleet/agents` parent before an environment read or tmux call. The projection writer uses `lstat` before chmod/write processing and rejects a symlinked directory without creating generated/local/quarantine files or deleting legacy input. The heartbeat sidecar defers to a fresh non-symlink native marker and falls back when stale/absent. Focused green evidence before independent review: `bash packages/mosaic/framework/tools/fleet/test-start-agent-session.sh` and `pnpm --dir packages/mosaic test -- src/fleet/generated-env-boundary.spec.ts` (11 tests) passed.
+- **Independent-review follow-up red-first:** Codex code review returned one blocker and security review one medium CWE-732 finding: the writer repaired an already `0777` directory with `chmod` before trusting its contents. Added a reproducer with a safe local file beneath an existing `0777` directory. Before the follow-up fix, `pnpm --dir packages/mosaic test -- src/fleet/generated-env-boundary.spec.ts` failed because the promise resolved and wrote `coder0.env.generated` instead of rejecting.
+- **Independent-review remediation:** Existing directories now pass non-following private-directory validation before any read or chmod; only a directory created in this call is normalized to `0700`. The fleet-add test fixture now creates its simulated trusted `fleet/agents` boundary at `0700`; this corrects fixture setup to match the new required contract rather than weakening the rejection assertion. Focused reruns passed: generated-boundary 12 tests, launcher boundary suite, and fleet suite 192 tests.
+- **Final verification before re-review:** Launcher + systemd suites passed; package suite passed (52 files, 754 tests); package lint/typecheck, root typecheck (42 tasks), format check, and diff check passed. The rerun code review still reports a tmux command-arity blocker, and the security rerun reports systemd `EnvironmentFile` pre-validation injection findings for both agent units. These were discovered after the specified three-remediation scope; no additional source changes were made. Independent review therefore remains `REQUEST CHANGES` despite the requested three fixes passing their behavioral suites.
+
+## Systemd pre-validation remediation (2026-07-14)
+
+- **Red-first:** Updated the fleet unit contract to reject any `EnvironmentFile=` projection preload, require a cleared bootstrap environment, and require a validated exact-stop path. Before implementation, `bash packages/mosaic/framework/systemd/user/test-fleet-units.sh` failed: `FAIL: agent units must not preload projections before strict parsing`.
+- **Red-first parser/stop coverage:** Added interaction-wrapper and exact-stop cases to the launcher boundary suite. Before implementation, `bash packages/mosaic/framework/tools/fleet/test-start-agent-session.sh` failed: `FAIL: interaction did not use shared strict parser first`, because the interaction wrapper consumed inherited environment before projection validation.
+- **Focused green:** Both unit templates now use `env -i` with fixed `HOME`, agent instance, and PATH; neither has `Environment=`/`EnvironmentFile=`. The interaction wrapper delegates to `start-agent-session.sh --interaction`, so strict generated/local parsing precedes pinned Pi profile checks. `--stop` reuses the strict generated parser before exact `=<agent>` socket/session termination. Passed: systemd unit suite, launcher boundary suite (including malformed interaction, pinned profile, and ambient-socket stop cases), and 210 focused TypeScript tests.
+- **Final verification:** `pnpm --dir packages/mosaic test` passed (52 files, 754 tests); package lint/typecheck, root typecheck (42 tasks), format/diff, and shell syntax checks passed. Security review passed with no findings. Code review repeated the previously refuted tmux argv concern and a pre-existing Claude trust-lock suggestion; per the assigned narrow follow-up, no tmux or unrelated trust-path change was made.
+
+## Risks and next review
+
+- This card is uncommitted and unreleased. The canonical tracker still records its dependencies as
+  M1-002 in progress and M1-003 not started; this continuation does not reinterpret those task states.
+- Final post-documentation checks passed: `pnpm --dir packages/mosaic typecheck`,
+  `pnpm --dir packages/mosaic lint`, `pnpm --dir packages/mosaic test` (52 files, 752 tests),
+  `pnpm typecheck` (42 Turbo tasks), and `pnpm format:check`.
+- Obtain independent code and security review of the complete delta next. Do not run commit, push,
+  PR, or live-fleet commands in this continuation.
+
+## Fresh-install directory remediation (2026-07-14)
+
+- **Objective:** Remediate only the fresh-install path where `installFleet` created `fleet/agents`
+  with host-umask permissions before the boundary writer correctly rejected it.
+- **Plan:** Add a real `fleet install --no-enable` integration reproducer; prove red; let the
+  existing boundary writer own directory creation; run focused and full gates. No commit, push,
+  PR, review disposition, or live-fleet action.
+- **Red evidence:** Before the one-line remediation,
+  `pnpm --dir packages/mosaic test -- src/commands/fleet.spec.ts` failed the new test with
+  `AgentEnvBoundaryError: code=unsafe-permissions` at `ensurePrivateProjectionDirectory`, after
+  `installFleet` pre-created the directory.
+- **Change:** Removed only the recursive `mkdir(activePaths.agentEnvDir)` in `installFleet`.
+  `writeAgentEnvironmentProjection` remains the sole creator and retains its existing `lstat`,
+  private-directory, symlink, and existing-unsafe-directory fail-closed checks.
+- **Focused green:** `pnpm --dir packages/mosaic test -- src/commands/fleet.spec.ts` — 193 tests
+  passed. The new integration executes a fresh `fleet install --no-enable`, asserts a real
+  non-symlink `0700` directory and a `0600` generated projection. Existing unsafe-directory
+  coverage remains in `generated-env-boundary.spec.ts` and asserts no chmod repair/no generated
+  file write.
+- **Full gates green:** generated-boundary 12 tests; launcher and systemd suites; package
+  typecheck/lint and 52 files / 755 tests; root typecheck (42 tasks), lint, format, diff check,
+  and root test (42 tasks) all passed.
+- **Independent review:** The complete inherited uncommitted delta still has Codex `REQUEST CHANGES`
+  findings outside this narrow fix (tmux command arity and Claude trust-lock regression), plus a
+  security-review medium finding on unvalidated writable ancestor directories. No out-of-scope
+  source changes were made.
+- **Risk:** The writer's existing create-then-validate sequence is relied on for the creation
+  boundary; a concurrent substitution causes fail-closed validation rather than repair. The
+  review findings above remain residual risks for the complete card delta.

packages/mosaic/framework/fleet/README.md

@@ -9,7 +9,8 @@ package, normally at:
 ```
 
 The default tmux socket is `mosaic-fleet` so fleet commands do not touch the
-default tmux server.
+default tmux server. The roster is the desired-state authority; generated environment files are
+rebuildable projections, never a second source of configuration.
 
 ## Examples
 
@@ -31,6 +32,17 @@ The installed `tools/fleet/print-interaction-effective-policy.sh` prints only
 the resolved name, runtime, model, reasoning, and tool policy. It never reads
 or prints credential variables.
 
+## Generated agent environment boundary
+
+`mosaic fleet install` writes a private deterministic projection at
+`~/.config/mosaic/fleet/agents/<agent>.env.generated`. It may relocate only approved local machine
+data to `<agent>.env.local`; generated keys, arbitrary commands, secret-like keys, duplicate keys,
+unknown keys, and unsafe permissions fail before a tmux session is created. Legacy `.env` input is
+regenerated, relocated, or quarantined and is not a launch authority.
+
+See [`docs/fleet/reference/generated-env-boundary.md`](../../../../docs/fleet/reference/generated-env-boundary.md)
+for allowed local keys and the USC downstream interface evidence.
+
 Initialize a roster:
 
 ```bash

packages/mosaic/framework/fleet/roles/LIBRARY.md

@@ -12,19 +12,22 @@ on demand. Engineering personas have no explicit `domain:` marker (they are the
 implicit `engineering` domain); cross-domain personas carry a `domain:` key in
 their intro so tooling can group them.
 
-> This file is an index only — no code imports it. To add a persona, drop a new
+> This file is an index, not an authority source. The fleet persona resolver reads
-> `*.md` next to the others (mirroring the existing structure) and add a row here.
+> its rows for discovery compatibility, then requires a readable `*.md` contract;
+> authority is derived from canonical class metadata in code, never from this prose.
 
 ## engineering
 
 | Persona         | Purpose                                                                        |
 | --------------- | ------------------------------------------------------------------------------ |
 | orchestrator    | Always-on coordinator — runs the supervisor loop, dispatches ready work        |
+| team-leader     | Coordinates only orchestrator-leased capacity for one bounded project          |
 | board           | Multi-lens deliberation panel; owns the mission's direction, not its execution |
 | planner         | Turns ratified objectives into a phased FR plan wired into a `depends_on` DAG  |
 | decomposition   | Splits FRs into one-PR-each cards wired with `depends_on` edges                |
 | code            | Primary executor — one card, one branch, one PR to green CI                    |
 | review          | Correctness reviewer — judges an open PR on correctness, scope, and coverage   |
+| validator       | Independent final evidence certificate; never approves-to-land or merges       |
 | security-review | Second line of review — secrets, auth, and forbidden-path safety               |
 | site-tester     | Runtime verifier — runs the change and checks behavior vs. acceptance criteria |
 | documentation   | Prose maintainer — keeps human-facing docs and projections in sync             |
@@ -33,6 +36,7 @@ their intro so tooling can group them.
 | operator        | Escalation and control surface — owns exceptions and the fleet pause switch    |
 | session-review  | Post-task retrospective — turns finished work into improvement signals         |
 | enhancer        | Continuous-improvement loop — upgrades the fleet's tools, skills, and harness  |
+| interaction     | Operator request/status surface; routes orchestration and merge decisions      |
 
 ## executive
 

packages/mosaic/framework/fleet/roles/interaction.md

@@ -0,0 +1,16 @@
+# Interaction — fleet role definition
+
+The **interaction** role (`class: interaction`) is the operator-facing request and status surface for Mosaic.
+
+## Mandate
+
+1. Receive operator requests and present observable fleet or runtime status.
+2. Route orchestration requests to the orchestrator and merge decisions to the merge-gate.
+3. Report supported actions and their outcomes without claiming another role's authority.
+
+## Boundaries
+
+- Request/status only; it does not orchestrate, issue leases, approve-to-land, or merge.
+- It does not mutate roster configuration, role authority, or credentials.
+- A configured instance name such as Tess is display data, never a class or authority source.
+- `operator-interaction` remains a compatibility alias for this canonical class.

packages/mosaic/framework/fleet/roles/team-leader.md

@@ -0,0 +1,16 @@
+# Team leader — fleet role definition
+
+The **team-leader** (`class: team-leader`) coordinates a bounded project team using only capacity granted by an orchestrator-issued lease.
+
+## Mandate
+
+1. Direct the leased coder, reviewer, and validator capacity for the assigned project scope.
+2. Track delivery status and return results or blockers to the orchestrator.
+3. Stop using capacity when the lease or assignment ends.
+
+## Boundaries
+
+- Leased capacity only; this role does not issue or expand its own lease.
+- It cannot change fleet roster membership, role authority, fleet configuration, or credentials.
+- It cannot approve-to-land or merge.
+- It does not displace the orchestrator's topology and lease authority.

packages/mosaic/framework/fleet/roles/validator.md

@@ -0,0 +1,16 @@
+# Validator — fleet role definition
+
+The **validator** (`class: validator`) is the independent final evidence seat. It examines the accepted requirements, test evidence, review record, and candidate head and may issue a validation certificate for that exact evidence set.
+
+## Mandate
+
+1. Validate acceptance evidence independently from the implementation author.
+2. Issue or withhold a final validation certificate for the reviewed candidate.
+3. Report missing, stale, or contradictory evidence without altering it.
+
+## Boundaries
+
+- **Certificate only:** the validator does not approve-to-land or merge.
+- It does not replace correctness or security review.
+- It does not write product code, mutate the roster, issue leases, or access credentials.
+- A configured instance name such as Ultron is display data, never a class or authority source.

packages/mosaic/framework/systemd/user/README.md

@@ -24,45 +24,56 @@ The agent template calls:
 
 which starts or reuses a tmux session on `MOSAIC_TMUX_SOCKET`.
 
-## Local customization
+## Generated environment and local data
 
-Per-agent overrides live outside the package in:
+The roster-derived projection is written outside the package at:
 
 ```text
-~/.config/mosaic/fleet/agents/<agent>.env
+~/.config/mosaic/fleet/agents/<agent>.env.generated
 ```
 
-Example:
+Systemd does not read either environment file. It starts the launcher with a fixed cleared bootstrap
+environment; before it creates, queries, or stops an exact agent tmux session, `start-agent-session.sh`
+strictly parses the generated projection and the optional local data file:
 
-```dotenv
+```text
-MOSAIC_TMUX_SOCKET=mosaic-fleet
+~/.config/mosaic/fleet/agents/<agent>.env.local
-MOSAIC_AGENT_RUNTIME=claude
-MOSAIC_AGENT_WORKDIR=$HOME/src/your-project
-# Optional escape hatch for PoC/canary agents:
-# MOSAIC_AGENT_COMMAND=mosaic yolo claude
 ```
 
+The local file may contain only safe machine-specific data (`MOSAIC_RUNTIME_BIN`, heartbeat paths or
+interval, and Claude configuration paths). It cannot override roster-derived keys, carry a command,
+or contain secret-like/unknown keys. Both files must be private regular files. Do not hand-edit the
+generated projection; update the roster and regenerate it instead. A legacy `<agent>.env` is
+consumed only for regeneration, strict relocation, or private quarantine and is never launch input.
+
+See `docs/fleet/reference/generated-env-boundary.md` for the full contract.
+
 ## Manual canary sequence
 
-```bash
+Use the roster and the supported installer; do not pre-create the agent environment directory or
-mkdir -p ~/.config/systemd/user ~/.config/mosaic/tools/fleet ~/.config/mosaic/fleet/agents
+edit a generated projection. `mosaic fleet install` validates the roster, installs the units and
-cp packages/mosaic/framework/systemd/user/mosaic-*.service ~/.config/systemd/user/
+helpers, and writes private roster-derived projections before any service is started.
-cp packages/mosaic/framework/tools/fleet/*.sh ~/.config/mosaic/tools/fleet/
-chmod +x ~/.config/mosaic/tools/fleet/*.sh
-systemctl --user daemon-reload
-systemctl --user start mosaic-tmux-holder.service
-systemctl --user start mosaic-agent@canary.service
-tmux -L mosaic-fleet ls
 
-# For an operator-interaction service, the roster/env identity selects the
+```bash
-# generic unit instance; no service source is renamed for an instance.
+# Create a site-owned canary roster. Inspect an existing roster before using --force.
+mosaic fleet init --profile minimal --write
+mosaic fleet install
+systemctl --user daemon-reload
+mosaic fleet start canary-pi
+tmux -L mosaic-fleet ls
+```
+
+For an operator-interaction service, first put `<agent-name>` in the roster with the pinned Pi
+runtime, model, reasoning, and `operator-interaction` tool policy. Re-run `mosaic fleet install` after
+that roster change so it writes `<agent-name>.env.generated`; ambient `MOSAIC_AGENT_*` values are not
+launch authority. The generic unit instance uses that generated identity, and no service source is
+renamed for an instance:
+
+```bash
+mosaic fleet install
+systemctl --user daemon-reload
 systemctl --user start mosaic-interaction-agent@<agent-name>.service
-MOSAIC_AGENT_NAME=<agent-name> \
+~/.config/mosaic/tools/fleet/print-interaction-effective-policy.sh <agent-name>
-MOSAIC_AGENT_RUNTIME=pi \
-MOSAIC_AGENT_MODEL=openai/gpt-5.6-sol \
-MOSAIC_AGENT_REASONING=high \
-MOSAIC_AGENT_TOOL_POLICY=operator-interaction \
-  ~/.config/mosaic/tools/fleet/print-interaction-effective-policy.sh
 ```
 
 Do not use `tmux kill-server` without `-L mosaic-fleet`; this pattern is meant

packages/mosaic/framework/systemd/user/mosaic-agent@.service

@@ -7,16 +7,13 @@ PartOf=mosaic-tmux-holder.service
 
 [Service]
 Type=oneshot
+# Remove loader and noninteractive-shell controls before ExecStart loads env.
+UnsetEnvironment=LD_PRELOAD BASH_ENV ENV
 RemainAfterExit=yes
-# No default MOSAIC_TMUX_SOCKET: an absent roster socket means the literal
+# Never preload the projection. The launcher starts from a fixed minimal
-# default tmux socket (no -L). The per-agent .env sets it when the roster names
+# environment and strictly validates generated/local data before tmux effects.
-# one; otherwise it stays unset and start-agent-session.sh uses the default socket.
+ExecStart=/usr/bin/env -i HOME=%h MOSAIC_AGENT_NAME=%i PATH=/usr/bin:/bin /bin/bash --noprofile --norc %h/.config/mosaic/tools/fleet/start-agent-session.sh %i
-Environment=MOSAIC_AGENT_NAME=%i
+ExecStop=-/usr/bin/env -i HOME=%h MOSAIC_AGENT_NAME=%i PATH=/usr/bin:/bin /bin/bash --noprofile --norc %h/.config/mosaic/tools/fleet/start-agent-session.sh --stop %i
-Environment=MOSAIC_AGENT_RUNTIME=pi
-Environment=MOSAIC_AGENT_WORKDIR=%h
-EnvironmentFile=-%h/.config/mosaic/fleet/agents/%i.env
-ExecStart=/bin/bash %h/.config/mosaic/tools/fleet/start-agent-session.sh %i
-ExecStop=-/bin/bash -lc 'if [ -n "${MOSAIC_TMUX_SOCKET:-}" ]; then tmux -L "$MOSAIC_TMUX_SOCKET" kill-session -t "=%i"; else tmux kill-session -t "=%i"; fi'
 
 [Install]
 WantedBy=default.target

packages/mosaic/framework/systemd/user/mosaic-interaction-agent@.service

@@ -7,11 +7,13 @@ PartOf=mosaic-tmux-holder.service
 
 [Service]
 Type=oneshot
+# Remove loader and noninteractive-shell controls before ExecStart loads env.
+UnsetEnvironment=LD_PRELOAD BASH_ENV ENV
 RemainAfterExit=yes
-Environment=MOSAIC_AGENT_NAME=%i
+# The interaction wrapper delegates to the shared strict parser before pinned
-EnvironmentFile=%h/.config/mosaic/fleet/agents/%i.env
+# profile checks; no projection data reaches Bash through systemd.
-ExecStart=/bin/bash %h/.config/mosaic/tools/fleet/start-interaction-service.sh %i
+ExecStart=/usr/bin/env -i HOME=%h MOSAIC_AGENT_NAME=%i PATH=/usr/bin:/bin /bin/bash --noprofile --norc %h/.config/mosaic/tools/fleet/start-interaction-service.sh %i
-ExecStop=-/bin/bash -lc 'if [ -n "${MOSAIC_TMUX_SOCKET:-}" ]; then tmux -L "$MOSAIC_TMUX_SOCKET" kill-session -t "=%i"; else tmux kill-session -t "=%i"; fi'
+ExecStop=-/usr/bin/env -i HOME=%h MOSAIC_AGENT_NAME=%i PATH=/usr/bin:/bin /bin/bash --noprofile --norc %h/.config/mosaic/tools/fleet/start-agent-session.sh --stop %i
 
 [Install]
 WantedBy=default.target

packages/mosaic/framework/systemd/user/mosaic-tmux-holder.service

@@ -6,10 +6,11 @@ After=default.target
 [Service]
 Type=oneshot
 RemainAfterExit=yes
-Environment=MOSAIC_TMUX_SOCKET=mosaic-fleet
+# The holder owns the tmux server, so clear loader, shell-control, and stale
-Environment=MOSAIC_TMUX_HOLDER=_holder
+# manager/session variables before the server process starts.
-ExecStart=/bin/bash -lc 'tmux -L "$MOSAIC_TMUX_SOCKET" has-session -t "=${MOSAIC_TMUX_HOLDER}:0.0" 2>/dev/null || tmux -L "$MOSAIC_TMUX_SOCKET" new-session -d -s "$MOSAIC_TMUX_HOLDER" "while true; do sleep 3600; done"'
+UnsetEnvironment=LD_PRELOAD BASH_ENV ENV
-ExecStop=-/bin/bash -lc 'tmux -L "$MOSAIC_TMUX_SOCKET" kill-server'
+ExecStart=/usr/bin/env -i HOME=%h PATH=/usr/bin:/bin MOSAIC_TMUX_SOCKET=mosaic-fleet MOSAIC_TMUX_HOLDER=_holder /bin/bash --noprofile --norc %h/.config/mosaic/tools/fleet/start-tmux-holder.sh
+ExecStop=-/usr/bin/env -i HOME=%h PATH=/usr/bin:/bin MOSAIC_TMUX_SOCKET=mosaic-fleet /bin/bash --noprofile --norc -c 'tmux -L "$MOSAIC_TMUX_SOCKET" kill-server'
 
 [Install]
 WantedBy=default.target

packages/mosaic/framework/systemd/user/test-fleet-units.sh

@@ -5,6 +5,8 @@ SCRIPT_DIR=$(cd -- "$(dirname -- "$0")" && pwd)
 HOLDER="$SCRIPT_DIR/mosaic-tmux-holder.service"
 AGENT="$SCRIPT_DIR/mosaic-agent@.service"
 INTERACTION="$SCRIPT_DIR/mosaic-interaction-agent@.service"
+HOLDER_START="$SCRIPT_DIR/../../tools/fleet/start-tmux-holder.sh"
+START_AGENT="$SCRIPT_DIR/../../tools/fleet/start-agent-session.sh"
 
 fail() {
   echo "FAIL: $*" >&2
@@ -14,16 +16,40 @@ fail() {
 [ -f "$HOLDER" ] || fail "missing mosaic-tmux-holder.service"
 [ -f "$AGENT" ] || fail "missing mosaic-agent@.service"
 [ -f "$INTERACTION" ] || fail "missing mosaic-interaction-agent@.service"
+[ -x "$HOLDER_START" ] || fail "missing executable start-tmux-holder.sh"
+[ -x "$START_AGENT" ] || fail "missing executable start-agent-session.sh"
 
 grep -qF 'ExecStart=' "$HOLDER" || fail "holder has no ExecStart"
 grep -qF 'tmux -L' "$HOLDER" || fail "holder does not use named tmux socket"
 grep -qF '_holder' "$HOLDER" || fail "holder session is not explicit"
+grep -qF 'UnsetEnvironment=LD_PRELOAD BASH_ENV ENV' "$HOLDER" || \
+  fail "holder does not remove loader and shell-control variables"
+grep -qF 'ExecStart=/usr/bin/env -i HOME=%h PATH=/usr/bin:/bin MOSAIC_TMUX_SOCKET=mosaic-fleet MOSAIC_TMUX_HOLDER=_holder /bin/bash --noprofile --norc %h/.config/mosaic/tools/fleet/start-tmux-holder.sh' "$HOLDER" || \
+  fail "holder does not clear manager environment before starting tmux"
+grep -qF 'ExecStop=-/usr/bin/env -i HOME=%h PATH=/usr/bin:/bin MOSAIC_TMUX_SOCKET=mosaic-fleet /bin/bash --noprofile --norc -c' "$HOLDER" || \
+  fail "holder stop does not clear manager environment"
+if grep -qF -- '/bin/bash -lc' "$HOLDER"; then
+  fail "holder must not start tmux through a login shell"
+fi
 grep -qF 'Requires=mosaic-tmux-holder.service' "$AGENT" || fail "agent does not require holder"
 grep -qF 'start-agent-session.sh' "$AGENT" || fail "agent unit does not call start-agent-session.sh"
-grep -qF 'kill-session -t "=%i"' "$AGENT" || fail "agent stop does not exact-match its session"
+if grep -qE '^Environment(File)?=' "$AGENT" "$INTERACTION"; then
+  fail "agent units must not accept ambient or projection environment before strict parsing"
+fi
+grep -qF 'UnsetEnvironment=LD_PRELOAD BASH_ENV ENV' "$AGENT" || \
+  fail "agent unit does not remove loader and shell-control variables"
+grep -qF 'UnsetEnvironment=LD_PRELOAD BASH_ENV ENV' "$INTERACTION" || \
+  fail "interaction unit does not remove loader and shell-control variables"
+grep -qF 'ExecStart=/usr/bin/env -i HOME=%h MOSAIC_AGENT_NAME=%i PATH=/usr/bin:/bin /bin/bash --noprofile --norc' "$AGENT" || \
+  fail "agent unit does not clear bootstrap environment before strict parsing"
+grep -qF 'start-agent-session.sh --stop %i' "$AGENT" || \
+  fail "agent stop does not use the validated exact-stop path"
 grep -qF 'Requires=mosaic-tmux-holder.service' "$INTERACTION" || fail "interaction service does not require holder"
-grep -qF 'EnvironmentFile=%h/.config/mosaic/fleet/agents/%i.env' "$INTERACTION" || fail "interaction service does not require per-agent config"
+grep -qF 'ExecStart=/usr/bin/env -i HOME=%h MOSAIC_AGENT_NAME=%i PATH=/usr/bin:/bin /bin/bash --noprofile --norc' "$INTERACTION" || \
-grep -qF 'start-interaction-service.sh %i' "$INTERACTION" || fail "interaction service does not validate before startup"
+  fail "interaction unit does not clear bootstrap environment before strict parsing"
+grep -qF 'start-interaction-service.sh %i' "$INTERACTION" || fail "interaction service does not use shared strict parsing"
+grep -qF 'start-agent-session.sh --stop %i' "$INTERACTION" || \
+  fail "interaction stop does not use the validated exact-stop path"
 
 if command -v systemd-analyze >/dev/null 2>&1; then
   systemd-analyze verify --user "$HOLDER" "$AGENT" "$INTERACTION" >/tmp/mosaic-fleet-systemd-verify.log 2>&1 || {
@@ -32,4 +58,102 @@ if command -v systemd-analyze >/dev/null 2>&1; then
   }
 fi
 
+# Real isolated socket regression: a preexisting server with an LD_PRELOAD
+# constructor marker must fail closed, while a fresh named server is created.
+if command -v tmux >/dev/null 2>&1 && command -v cc >/dev/null 2>&1; then
+  TEST_ROOT=$(mktemp -d)
+  TEST_SOCKET="mosaic-holder-test-$$"
+  trap 'tmux -L "$TEST_SOCKET" kill-server >/dev/null 2>&1 || true; rm -rf "$TEST_ROOT"' EXIT
+  MARKER="$TEST_ROOT/loader-marker"
+  LIBRARY="$TEST_ROOT/marker.so"
+  HOLDER_HOME="$TEST_ROOT/holder-home"
+  mkdir -p "$HOLDER_HOME/.config/mosaic/fleet/run"
+  chmod 700 "$HOLDER_HOME/.config" "$HOLDER_HOME/.config/mosaic" \
+    "$HOLDER_HOME/.config/mosaic/fleet" "$HOLDER_HOME/.config/mosaic/fleet/run"
+  printf '123e4567-e89b-12d3-a456-426614174000\n' > \
+    "$HOLDER_HOME/.config/mosaic/fleet/run/holder-owner"
+  chmod 600 "$HOLDER_HOME/.config/mosaic/fleet/run/holder-owner"
+  cat > "$TEST_ROOT/marker.c" <<'EOF'
+#include <fcntl.h>
+#include <stdlib.h>
+#include <unistd.h>
+__attribute__((constructor)) static void mark_loader(void) {
+  const char *path = getenv("MOSAIC_LOADER_MARKER");
+  if (path != NULL) {
+    int fd = open(path, O_WRONLY | O_CREAT | O_APPEND, 0600);
+    if (fd >= 0) { write(fd, "loaded\\n", 7); close(fd); }
+  }
+}
+EOF
+  cc -shared -fPIC -o "$LIBRARY" "$TEST_ROOT/marker.c"
+  MOSAIC_LOADER_MARKER="$MARKER" LD_PRELOAD="$LIBRARY" \
+    tmux -L "$TEST_SOCKET" new-session -d -s _holder 'sleep 60'
+  [ -s "$MARKER" ] || fail "contaminated fixture did not execute loader constructor"
+  server_pid=$(tmux -L "$TEST_SOCKET" display-message -p '#{pid}')
+  : > "$MARKER"
+  if /usr/bin/env -i HOME="$HOLDER_HOME" PATH=/usr/bin:/bin \
+    MOSAIC_TMUX_SOCKET="$TEST_SOCKET" MOSAIC_TMUX_HOLDER=_holder "$HOLDER_START" \
+    >"$TEST_ROOT/holder.out" 2>&1; then
+    fail "holder adopted contaminated named server"
+  fi
+  grep -qF 'global environment does not match the owned-server contract' "$TEST_ROOT/holder.out" || \
+    fail "holder did not report contaminated server environment"
+  [ "$(tmux -L "$TEST_SOCKET" display-message -p '#{pid}')" = "$server_pid" ] || \
+    fail "holder replaced a contaminated server instead of failing closed"
+  [ ! -s "$MARKER" ] || fail "holder execution triggered a contaminated loader"
+
+  # Agent validation must reject the same unmanaged server without cleaning its
+  # global environment or adding a managed session.
+  AGENT_HOME="$HOLDER_HOME/.config/mosaic"
+  AGENT_NAME=loader-safe
+  AGENT_WORKDIR="$AGENT_HOME/work"
+  AGENT_BIN="$TEST_ROOT/agent-bin"
+  mkdir -p "$AGENT_HOME/fleet/agents" "$AGENT_WORKDIR" "$AGENT_BIN"
+  chmod 700 "$AGENT_HOME/fleet/agents"
+  cat > "$AGENT_HOME/fleet/agents/$AGENT_NAME.env.generated" <<EOF
+MOSAIC_AGENT_NAME=$AGENT_NAME
+MOSAIC_AGENT_CLASS=code
+MOSAIC_AGENT_RUNTIME=pi
+MOSAIC_AGENT_MODEL=
+MOSAIC_AGENT_REASONING=
+MOSAIC_AGENT_TOOL_POLICY=code
+MOSAIC_AGENT_WORKDIR=$AGENT_WORKDIR
+MOSAIC_TMUX_SOCKET=$TEST_SOCKET
+EOF
+  printf 'MOSAIC_RUNTIME_BIN=%s\n' "$AGENT_BIN" > "$AGENT_HOME/fleet/agents/$AGENT_NAME.env.local"
+  chmod 600 "$AGENT_HOME/fleet/agents/$AGENT_NAME.env.generated" \
+    "$AGENT_HOME/fleet/agents/$AGENT_NAME.env.local"
+  cat > "$AGENT_BIN/mosaic" <<'EOF'
+#!/bin/sh
+sleep 30
+EOF
+  chmod 700 "$AGENT_BIN/mosaic"
+  server_environment_before=$(tmux -L "$TEST_SOCKET" show-environment -g | sort)
+  server_sessions_before=$(tmux -L "$TEST_SOCKET" list-sessions | sort)
+  if /usr/bin/env -i HOME="$HOLDER_HOME" PATH=/usr/bin:/bin MOSAIC_HOME="$AGENT_HOME" \
+    "$START_AGENT" "$AGENT_NAME" >"$TEST_ROOT/agent.out" 2>&1; then
+    fail "agent launcher adopted contaminated named server"
+  fi
+  [ "$(tmux -L "$TEST_SOCKET" display-message -p '#{pid}')" = "$server_pid" ] || \
+    fail "agent launcher changed unmanaged server PID"
+  [ "$(tmux -L "$TEST_SOCKET" show-environment -g | sort)" = "$server_environment_before" ] || \
+    fail "agent launcher changed unmanaged global environment"
+  [ "$(tmux -L "$TEST_SOCKET" list-sessions | sort)" = "$server_sessions_before" ] || \
+    fail "agent launcher changed unmanaged sessions"
+  tmux -L "$TEST_SOCKET" kill-server
+  /usr/bin/env -i HOME="$HOLDER_HOME" PATH=/usr/bin:/bin \
+    MOSAIC_TMUX_SOCKET="$TEST_SOCKET" MOSAIC_TMUX_HOLDER=_holder "$HOLDER_START"
+  tmux -L "$TEST_SOCKET" has-session -t '=_holder:0.0' || fail "fresh holder was not created"
+  if tmux -L "$TEST_SOCKET" show-environment -g LD_PRELOAD 2>/dev/null | grep -q '^LD_PRELOAD='; then
+    fail "fresh holder retained LD_PRELOAD"
+  fi
+  /usr/bin/env -i HOME="$HOLDER_HOME" PATH=/usr/bin:/bin MOSAIC_HOME="$AGENT_HOME" \
+    "$START_AGENT" "$AGENT_NAME"
+  tmux -L "$TEST_SOCKET" has-session -t "=$AGENT_NAME:0.0" || \
+    fail "agent did not launch on a valid owned server"
+  tmux -L "$TEST_SOCKET" kill-server
+  trap - EXIT
+  rm -rf "$TEST_ROOT"
+fi
+
 echo "ok - fleet systemd unit templates"

packages/mosaic/framework/tools/fleet/start-agent-session.sh

@@ -1,39 +1,207 @@
 #!/usr/bin/env bash
 set -euo pipefail
 
-AGENT_NAME=${1:-${MOSAIC_AGENT_NAME:-}}
+# FCM-M2-001 boundary: only a roster-derived .env.generated projection and a
-# Absent socket ⇒ the LITERAL default tmux socket (no -L). The roster's
+# separately parsed data-only .env.local can influence launch. Never source an
-# socket_name is honored when set; absent never silently becomes mosaic-fleet
+# environment file and never accept a command string from either file.
-# (spawn stays consistent with the onboarding cheat-sheet + fleet ps observe).
-MOSAIC_TMUX_SOCKET=${MOSAIC_TMUX_SOCKET:-}
-MOSAIC_AGENT_RUNTIME=${MOSAIC_AGENT_RUNTIME:-pi}
-MOSAIC_AGENT_MODEL=${MOSAIC_AGENT_MODEL:-}
-MOSAIC_AGENT_REASONING=${MOSAIC_AGENT_REASONING:-}
-MOSAIC_AGENT_WORKDIR=${MOSAIC_AGENT_WORKDIR:-$HOME}
-MOSAIC_AGENT_COMMAND=${MOSAIC_AGENT_COMMAND:-}
-MOSAIC_HEARTBEAT_RUN_DIR=${MOSAIC_HEARTBEAT_RUN_DIR:-${MOSAIC_HOME:-$HOME/.config/mosaic}/fleet/run}
-MOSAIC_HEARTBEAT_INTERVAL=${MOSAIC_HEARTBEAT_INTERVAL:-15}
 
-if [ -z "$AGENT_NAME" ]; then
+MODE=launch
-  echo "ERROR: agent name argument or MOSAIC_AGENT_NAME is required" >&2
+case "${1:-}" in
-  exit 64
+  --stop)
-fi
+    MODE=stop
-
+    AGENT_NAME=${2:-}
-case "$MOSAIC_AGENT_REASONING" in
-  ''|low|medium|high) ;;
-  *)
-    echo "ERROR: MOSAIC_AGENT_REASONING must be low, medium, or high" >&2
-    exit 64
     ;;
+  --interaction)
+    MODE=interaction
+    AGENT_NAME=${2:-}
+    ;;
+  *) AGENT_NAME=${1:-${MOSAIC_AGENT_NAME:-}} ;;
 esac
+MOSAIC_HOME=${MOSAIC_HOME:-$HOME/.config/mosaic}
+
+fail() {
+  echo "ERROR: $*" >&2
+  exit 64
+}
+
+hash_value() {
+  printf '%s' "$1" | sha256sum | awk '{print $1}'
+}
+
+fail_env() {
+  local code="$1"
+  local key="$2"
+  local value="$3"
+  echo "ERROR: agent environment rejected: code=${code} key=${key} sha256=$(hash_value "$value")" >&2
+  exit 64
+}
+
+safe_agent_name() {
+  [[ "$1" =~ ^[A-Za-z0-9][A-Za-z0-9_.-]*$ ]]
+}
+
+safe_policy_name() {
+  [[ "$1" =~ ^[a-z][a-z0-9-]*$ ]]
+}
+
+safe_path() {
+  [[ "$1" == /* ]] || return 1
+  [[ "$1" != *".."* ]] || return 1
+  [[ ! "$1" =~ [[:space:]\"\'\`\$\\\;\|\&\<\>\(\)\{\}] ]]
+}
+
+assert_private_regular_file() {
+  local file="$1"
+  [ -f "$file" ] && [ ! -L "$file" ] || fail_env unsafe-file '(file)' "$file"
+  local mode
+  mode=$(stat -c '%a' -- "$file") || fail_env unsafe-file '(file)' "$file"
+  (( (8#$mode & 8#077) == 0 )) || fail_env unsafe-permissions '(file)' "$file"
+}
+
+assert_managed_directory() {
+  local directory="$1"
+  [ -d "$directory" ] && [ ! -L "$directory" ] || fail_env unsafe-directory '(directory)' "$directory"
+  local mode
+  mode=$(stat -c '%a' -- "$directory") || fail_env unsafe-directory '(directory)' "$directory"
+  (( (8#$mode & 8#022) == 0 )) || fail_env unsafe-permissions '(directory)' "$directory"
+}
+
+assert_private_directory() {
+  local directory="$1"
+  assert_managed_directory "$directory"
+  local mode
+  mode=$(stat -c '%a' -- "$directory") || fail_env unsafe-directory '(directory)' "$directory"
+  (( (8#$mode & 8#077) == 0 )) || fail_env unsafe-permissions '(directory)' "$directory"
+}
+
+[ -n "$AGENT_NAME" ] || fail "agent name argument or MOSAIC_AGENT_NAME is required"
+safe_agent_name "$AGENT_NAME" || fail_env unsafe-agent-name MOSAIC_AGENT_NAME "$AGENT_NAME"
+safe_path "$MOSAIC_HOME" || fail_env unsafe-path MOSAIC_HOME "$MOSAIC_HOME"
+
+FLEET_DIR="$MOSAIC_HOME/fleet"
+AGENT_ENV_DIR="$FLEET_DIR/agents"
+assert_managed_directory "$MOSAIC_HOME"
+assert_managed_directory "$FLEET_DIR"
+assert_private_directory "$AGENT_ENV_DIR"
+
+GENERATED_ENV="$AGENT_ENV_DIR/$AGENT_NAME.env.generated"
+LOCAL_ENV="$AGENT_ENV_DIR/$AGENT_NAME.env.local"
+
+declare -A GENERATED_VALUES=()
+declare -A LOCAL_VALUES=()
+declare -A SEEN_KEYS=()
+
+is_sensitive_key() {
+  [[ "$1" =~ (API[_-]?KEY|AUTH|CREDENTIAL|PASSWORD|PRIVATE|SECRET|TOKEN) ]]
+}
+
+is_generated_key() {
+  case "$1" in
+    MOSAIC_AGENT_NAME|MOSAIC_AGENT_CLASS|MOSAIC_AGENT_RUNTIME|MOSAIC_AGENT_MODEL|MOSAIC_AGENT_REASONING|MOSAIC_AGENT_TOOL_POLICY|MOSAIC_AGENT_WORKDIR|MOSAIC_TMUX_SOCKET) return 0 ;;
+    *) return 1 ;;
+  esac
+}
+
+is_local_key() {
+  case "$1" in
+    MOSAIC_RUNTIME_BIN|MOSAIC_HEARTBEAT_RUN_DIR|MOSAIC_HEARTBEAT_INTERVAL|MOSAIC_CLAUDE_JSON|CLAUDE_CONFIG_DIR) return 0 ;;
+    *) return 1 ;;
+  esac
+}
+
+validate_generated_value() {
+  local key="$1"
+  local value="$2"
+  case "$key" in
+    MOSAIC_AGENT_NAME) safe_agent_name "$value" || fail_env unsafe-agent-name "$key" "$value" ;;
+    MOSAIC_AGENT_CLASS) safe_policy_name "$value" || fail_env unsafe-class "$key" "$value" ;;
+    MOSAIC_AGENT_RUNTIME)
+      case "$value" in claude|codex|opencode|pi) ;; *) fail_env unsupported-runtime "$key" "$value" ;; esac
+      ;;
+    MOSAIC_AGENT_MODEL) [[ "$value" =~ ^[A-Za-z0-9._/:+-]*$ ]] || fail_env unsafe-model "$key" "$value" ;;
+    MOSAIC_AGENT_REASONING)
+      case "$value" in ''|low|medium|high) ;; *) fail_env unsupported-reasoning "$key" "$value" ;; esac
+      ;;
+    MOSAIC_AGENT_TOOL_POLICY) [ -z "$value" ] || safe_policy_name "$value" || fail_env unsafe-tool-policy "$key" "$value" ;;
+    MOSAIC_AGENT_WORKDIR) safe_path "$value" || fail_env unsafe-path "$key" "$value" ;;
+    MOSAIC_TMUX_SOCKET) [[ "$value" =~ ^[A-Za-z0-9_.-]*$ ]] || fail_env unsafe-socket "$key" "$value" ;;
+  esac
+}
+
+validate_local_value() {
+  local key="$1"
+  local value="$2"
+  if [ "$key" = MOSAIC_HEARTBEAT_INTERVAL ]; then
+    [[ "$value" =~ ^[1-9][0-9]*$ ]] || fail_env invalid-interval "$key" "$value"
+  else
+    safe_path "$value" || fail_env unsafe-path "$key" "$value"
+  fi
+}
+
+load_environment_file() {
+  local file="$1"
+  local kind="$2"
+  [ -e "$file" ] || {
+    [ "$kind" = generated ] && fail_env missing-file '(generated)' "$file"
+    return 0
+  }
+  assert_private_regular_file "$file"
+  SEEN_KEYS=()
+
+  local line key value
+  while IFS= read -r line || [ -n "$line" ]; do
+    [ -z "$line" ] && continue
+    if [[ ! "$line" =~ ^([A-Z][A-Z0-9_]*)=(.*)$ ]]; then
+      fail_env malformed-line '(malformed)' "$line"
+    fi
+    key=${BASH_REMATCH[1]}
+    value=${BASH_REMATCH[2]}
+    [ -z "${SEEN_KEYS[$key]+set}" ] || fail_env duplicate-key "$key" "$value"
+    SEEN_KEYS[$key]=1
+    is_sensitive_key "$key" && fail_env sensitive-key "$key" "$value"
+
+    if [ "$kind" = generated ]; then
+      is_generated_key "$key" || fail_env unknown-key "$key" "$value"
+      validate_generated_value "$key" "$value"
+      GENERATED_VALUES[$key]=$value
+    else
+      is_generated_key "$key" && fail_env generated-key-shadow "$key" "$value"
+      is_local_key "$key" || fail_env unknown-key "$key" "$value"
+      validate_local_value "$key" "$value"
+      LOCAL_VALUES[$key]=$value
+    fi
+  done < "$file"
+}
+
+load_environment_file "$GENERATED_ENV" generated
+for required_key in \
+  MOSAIC_AGENT_NAME MOSAIC_AGENT_CLASS MOSAIC_AGENT_RUNTIME MOSAIC_AGENT_MODEL \
+  MOSAIC_AGENT_REASONING MOSAIC_AGENT_TOOL_POLICY MOSAIC_AGENT_WORKDIR MOSAIC_TMUX_SOCKET; do
+  [ -n "${GENERATED_VALUES[$required_key]+set}" ] || fail_env missing-key "$required_key" ''
+done
+load_environment_file "$LOCAL_ENV" local
+
+[ "${GENERATED_VALUES[MOSAIC_AGENT_NAME]}" = "$AGENT_NAME" ] || \
+  fail_env agent-name-mismatch MOSAIC_AGENT_NAME "${GENERATED_VALUES[MOSAIC_AGENT_NAME]}"
+
+MOSAIC_TMUX_SOCKET=${GENERATED_VALUES[MOSAIC_TMUX_SOCKET]}
+MOSAIC_AGENT_RUNTIME=${GENERATED_VALUES[MOSAIC_AGENT_RUNTIME]}
+MOSAIC_AGENT_MODEL=${GENERATED_VALUES[MOSAIC_AGENT_MODEL]}
+MOSAIC_AGENT_REASONING=${GENERATED_VALUES[MOSAIC_AGENT_REASONING]}
+MOSAIC_AGENT_WORKDIR=${GENERATED_VALUES[MOSAIC_AGENT_WORKDIR]}
+MOSAIC_AGENT_CLASS=${GENERATED_VALUES[MOSAIC_AGENT_CLASS]}
+MOSAIC_AGENT_TOOL_POLICY=${GENERATED_VALUES[MOSAIC_AGENT_TOOL_POLICY]}
+MOSAIC_RUNTIME_BIN=${LOCAL_VALUES[MOSAIC_RUNTIME_BIN]:-}
+MOSAIC_HEARTBEAT_RUN_DIR=${LOCAL_VALUES[MOSAIC_HEARTBEAT_RUN_DIR]:-$MOSAIC_HOME/fleet/run}
+MOSAIC_HEARTBEAT_INTERVAL=${LOCAL_VALUES[MOSAIC_HEARTBEAT_INTERVAL]:-15}
+MOSAIC_CLAUDE_JSON=${LOCAL_VALUES[MOSAIC_CLAUDE_JSON]:-}
+CLAUDE_CONFIG_DIR=${LOCAL_VALUES[CLAUDE_CONFIG_DIR]:-}
 
 if ! command -v tmux >/dev/null 2>&1; then
   echo "ERROR: tmux is required" >&2
   exit 69
 fi
 
-# tmux wrapper: pass -L only when a socket is configured. An absent/empty socket
-# means the default tmux socket (no -L), keeping spawn == observe == cheat-sheet.
 _tmux() {
   if [ -n "$MOSAIC_TMUX_SOCKET" ]; then
     tmux -L "$MOSAIC_TMUX_SOCKET" "$@"
@@ -42,140 +210,90 @@ _tmux() {
   fi
 }
 
+assert_owned_tmux_server() {
+  local owner_file="$MOSAIC_HOME/fleet/run/holder-owner"
+  [ -f "$owner_file" ] && [ ! -L "$owner_file" ] || fail "private tmux ownership identity is missing"
+  local owner_mode
+  owner_mode=$(stat -c '%a' -- "$owner_file") || fail "private tmux ownership identity is unreadable"
+  (( (8#$owner_mode & 8#077) == 0 )) || fail "private tmux ownership identity has unsafe permissions"
+  local owner
+  owner=$(tr -d '\n' < "$owner_file")
+  [[ "$owner" =~ ^[a-f0-9-]{36}$ ]] || fail "private tmux ownership identity is malformed"
+  _tmux has-session -t '=_holder:0.0' 2>/dev/null || fail "owned tmux holder session is absent"
+  local environment expected
+  environment=$(_tmux show-environment -g 2>/dev/null) || fail "owned tmux global environment is unreadable"
+  expected=$(printf '%s\n' \
+    "HOME=$HOME" \
+    'PATH=/usr/bin:/bin' \
+    "PWD=$HOME" \
+    "MOSAIC_FLEET_OWNER=$owner" \
+    'MOSAIC_TMUX_HOLDER=_holder' \
+    "MOSAIC_TMUX_SOCKET=$MOSAIC_TMUX_SOCKET" | sort)
+  [ "$(printf '%s\n' "$environment" | sort)" = "$expected" ] || \
+    fail "tmux server ownership or environment validation failed"
+}
+
+# Validate exact server ownership before querying, cleaning, or creating any
+# managed session. An unmanaged or contaminated named socket is never repaired.
+assert_owned_tmux_server
+
+if [ "$MODE" = interaction ]; then
+  [ "$MOSAIC_AGENT_RUNTIME" = pi ] || fail "operator interaction service requires runtime pi"
+  [ "$MOSAIC_AGENT_MODEL" = openai/gpt-5.6-sol ] || \
+    fail "operator interaction service requires the pinned model"
+  [ "$MOSAIC_AGENT_REASONING" = high ] || \
+    fail "operator interaction service requires high reasoning"
+  [ "$MOSAIC_AGENT_TOOL_POLICY" = operator-interaction ] || \
+    fail "operator interaction service requires the operator-interaction tool policy"
+fi
+
+if [ "$MODE" = stop ]; then
+  _tmux kill-session -t "=${AGENT_NAME}" >/dev/null 2>&1 || true
+  exit 0
+fi
+
 if _tmux has-session -t "=${AGENT_NAME}:0.0" 2>/dev/null; then
   echo "Mosaic agent session already running: $AGENT_NAME on socket ${MOSAIC_TMUX_SOCKET:-(default)}"
   exit 0
 fi
 
-if [ -z "$MOSAIC_AGENT_COMMAND" ]; then
+# Systemd passes HOME as %h, and the installed service fixes MOSAIC_HOME under
-  # Map the roster's per-agent model_hint to `--model` so workers launch on the
+# that home. Derive the pane home from the canonical path when available so an
-  # configured model (e.g. pi on openai-codex/gpt-5.5:high). Omitted when unset.
+# inherited pane/session HOME cannot become runtime authority.
-  MOSAIC_AGENT_COMMAND="mosaic yolo $MOSAIC_AGENT_RUNTIME${MOSAIC_AGENT_MODEL:+ --model $MOSAIC_AGENT_MODEL}${MOSAIC_AGENT_REASONING:+ --thinking $MOSAIC_AGENT_REASONING}"
+PANE_HOME=$HOME
-fi
+case "$MOSAIC_HOME" in
+  */.config/mosaic) PANE_HOME=${MOSAIC_HOME%/.config/mosaic} ;;
+esac
 
-# ── Derive a runtime-bin PATH prefix ─────────────────────────────────────────
-# Precedence:
-#   1. $MOSAIC_RUNTIME_BIN (explicit override)
-#   2. $(npm config get prefix)/bin  (if npm is on PATH)
-#   3. Fallbacks: $HOME/.npm-global/bin and $HOME/.local/bin
-#
-# Only directories that already exist are included.  The prefix is baked into
-# the pane command regardless of what the LAUNCHER process's $PATH contains,
-# because the tmux pane inherits the tmux SERVER environment (not this script's
-# environment).  A dir on the launcher's PATH may be absent from the server PATH,
-# so every existing candidate must always be included.  Dedup within the
-# constructed prefix avoids listing the same dir twice.
 _build_runtime_bin_prefix() {
   local candidates=()
-
+  if [ -n "$MOSAIC_RUNTIME_BIN" ]; then candidates+=("$MOSAIC_RUNTIME_BIN"); fi
-  if [ -n "${MOSAIC_RUNTIME_BIN:-}" ]; then
-    candidates+=("$MOSAIC_RUNTIME_BIN")
-  fi
-
   if command -v npm >/dev/null 2>&1; then
     local npm_prefix
     npm_prefix=$(npm config get prefix 2>/dev/null) || true
-    if [ -n "$npm_prefix" ]; then
+    if [ -n "$npm_prefix" ]; then candidates+=("${npm_prefix}/bin"); fi
-      candidates+=("${npm_prefix}/bin")
-    fi
   fi
+  candidates+=("$PANE_HOME/.npm-global/bin" "$PANE_HOME/.local/bin")
 
-  candidates+=("$HOME/.npm-global/bin")
+  local prefix="" dir
-  candidates+=("$HOME/.local/bin")
-
-  local prefix=""
   for dir in "${candidates[@]}"; do
     [ -d "$dir" ] || continue
-    if [ -z "$prefix" ]; then
+    case ":${prefix}:" in *":${dir}:"*) ;; *) prefix="${prefix:+$prefix:}$dir" ;; esac
-      prefix="$dir"
-    else
-      case ":${prefix}:" in
-        *":${dir}:"*) ;;  # already in our prefix — skip
-        *) prefix="${prefix}:${dir}" ;;
-      esac
-    fi
   done
-
   printf '%s' "$prefix"
 }
 
 MOSAIC_RUNTIME_BIN_PREFIX=$(_build_runtime_bin_prefix)
+PANE_PATH=${MOSAIC_RUNTIME_BIN_PREFIX:+${MOSAIC_RUNTIME_BIN_PREFIX}:}/usr/local/bin:/usr/bin:/bin
 
-# ── Build the pane command ────────────────────────────────────────────────────
-# The pane command must:
-#   - Export the augmented PATH so the runtime binary is found.
-#   - exec the agent command so the runtime is the pane's foreground process
-#     (makes `fleet ps` pane_current_command check reliable; no DRIFT false-positive).
-#
-# Quoting strategy: single-quote the inner shell snippet so that variable
-# references in MOSAIC_AGENT_COMMAND are NOT expanded here — they expand inside
-# the pane shell.  However, MOSAIC_RUNTIME_BIN_PREFIX and PATH must be expanded
-# NOW (in this script) because the pane shell inherits the tmux server
-# environment, not this script's env.
-#
-# We build the snippet as a double-quoted here-string embedded in a printf call
-# to avoid nested quoting problems.
-#
-# MOSAIC_AGENT_NAME must also be exported INTO the pane: panes inherit the tmux
-# server environment (not this script's, and not the systemd unit's), so the
-# name would otherwise be empty in-pane and the runtime's native heartbeat
-# (which gates on MOSAIC_AGENT_NAME) would never fire. %q-quote it so it is a
-# safe single bash token regardless of the name's characters.
-AGENT_NAME_Q=$(printf '%q' "$AGENT_NAME")
-
-# MOSAIC_AGENT_CLASS must ALSO be exported INTO the pane, for the same reason as
-# MOSAIC_AGENT_NAME above: the pane inherits the tmux SERVER environment (not this
-# script's env, and not the systemd unit's EnvironmentFile), so the per-agent class
-# written to agents/<name>.env would otherwise be invisible in-pane. The launcher
-# composes the persona contract from process.env.MOSAIC_AGENT_CLASS at launch
-# (compose-contract -> readPersonaContractBlock); without this export it sees an
-# undefined class and silently injects NO persona contract. %q-quote it so it is a
-# safe single bash token; an empty/unset class %q-quotes to '' and is a harmless
-# no-op downstream (readPersonaContractBlock returns '' for an empty class).
-AGENT_CLASS_Q=$(printf '%q' "${MOSAIC_AGENT_CLASS:-}")
-AGENT_TOOL_POLICY_Q=$(printf '%q' "${MOSAIC_AGENT_TOOL_POLICY:-}")
-
-if [ -n "$MOSAIC_RUNTIME_BIN_PREFIX" ]; then
-  PANE_SHELL_SNIPPET="export MOSAIC_AGENT_NAME=${AGENT_NAME_Q}; export MOSAIC_AGENT_CLASS=${AGENT_CLASS_Q}; export MOSAIC_AGENT_TOOL_POLICY=${AGENT_TOOL_POLICY_Q}; export PATH=\"${MOSAIC_RUNTIME_BIN_PREFIX}:\${PATH}\"; exec ${MOSAIC_AGENT_COMMAND}"
-else
-  PANE_SHELL_SNIPPET="export MOSAIC_AGENT_NAME=${AGENT_NAME_Q}; export MOSAIC_AGENT_CLASS=${AGENT_CLASS_Q}; export MOSAIC_AGENT_TOOL_POLICY=${AGENT_TOOL_POLICY_Q}; exec ${MOSAIC_AGENT_COMMAND}"
-fi
-
-mkdir -p "$MOSAIC_AGENT_WORKDIR"
-
-# ── Pre-trust the workdir for the Claude runtime ─────────────────────────────
-# Claude Code shows a one-time "Is this a project you trust?" folder-trust gate
-# the first time it opens a directory. A fleet-launched agent has no human to
-# answer it, so the pane stalls forever at the prompt while its heartbeat keeps
-# reporting "healthy" (the pane process IS alive — it's just blocked).
-#
-# IMPORTANT: --dangerously-skip-permissions does NOT bypass this gate, and
-# neither does `trustedProjectDirectories` in settings.json (verified empirically
-# 2026-06-24). The ONLY thing the gate honors is the per-project record in
-# ~/.claude.json: projects["<dir>"].hasTrustDialogAccepted == true (exactly what
-# answering the prompt writes). So we pre-seed that record here.
-#
-# Idempotent, atomic, best-effort: any failure is non-fatal (the agent still
-# launches — worst case it stalls on the gate, i.e. the pre-fix status quo).
-# Only the claude runtime needs this; codex/pi have no such gate.
 _ensure_claude_workdir_trusted() {
   local workdir="$1"
-  # The path claude keys on is the resolved cwd it is launched in.
+  local resolved
-  local rp
+  resolved=$(cd "$workdir" 2>/dev/null && pwd -P) || resolved="$workdir"
-  rp=$(cd "$workdir" 2>/dev/null && pwd -P) || rp="$workdir"
-  # ~/.claude.json lives next to the claude config dir; honor CLAUDE_CONFIG_DIR.
   local claude_json="${MOSAIC_CLAUDE_JSON:-${CLAUDE_CONFIG_DIR:+$CLAUDE_CONFIG_DIR/.claude.json}}"
   claude_json="${claude_json:-$HOME/.claude.json}"
-
+  command -v python3 >/dev/null 2>&1 || return 1
-  if ! command -v python3 >/dev/null 2>&1; then
+  MOSAIC_CJ="$claude_json" MOSAIC_TRUST_DIR="$resolved" python3 - <<'PY'
-    echo "WARNING: python3 not found; cannot pre-trust '$rp' for claude (agent may stall on the folder-trust gate)" >&2
-    return 1
-  fi
-
-  # Serialize concurrent agent launches that share ~/.claude.json (flock if available).
-  local lock="${claude_json}.mosaic-lock"
-  _seed() {
-    MOSAIC_CJ="$claude_json" MOSAIC_TRUST_DIR="$rp" python3 - <<'PY'
 import json, os, sys, tempfile
 cj = os.environ["MOSAIC_CJ"]
 d = os.environ["MOSAIC_TRUST_DIR"]
@@ -184,22 +302,19 @@ try:
     if not isinstance(data, dict):
         data = {}
 except Exception:
-    # Never corrupt an unreadable/partial file — bail without writing.
     sys.exit(2)
 projects = data.setdefault("projects", {})
 entry = projects.get(d)
 if not isinstance(entry, dict):
     entry = {}
     projects[d] = entry
-if entry.get("hasTrustDialogAccepted") is True:
-    sys.exit(0)  # already trusted — nothing to do
 entry["hasTrustDialogAccepted"] = True
 tmp_dir = os.path.dirname(cj) or "."
 fd, tmp = tempfile.mkstemp(dir=tmp_dir, prefix=".claude.json.mosaic.")
 try:
     with os.fdopen(fd, "w") as f:
         json.dump(data, f, indent=2)
-    os.replace(tmp, cj)  # atomic
+    os.replace(tmp, cj)
 except Exception:
     try:
         os.unlink(tmp)
@@ -207,56 +322,56 @@ except Exception:
         pass
     sys.exit(3)
 PY
-  }
-  if command -v flock >/dev/null 2>&1; then
-    ( flock 9; _seed ) 9>"$lock" 2>/dev/null || _seed
-  else
-    _seed
-  fi
 }
 
-case "$MOSAIC_AGENT_RUNTIME" in
+if [ "$MOSAIC_AGENT_RUNTIME" = claude ]; then
-  claude)
+  _ensure_claude_workdir_trusted "$MOSAIC_AGENT_WORKDIR" || \
-    _ensure_claude_workdir_trusted "$MOSAIC_AGENT_WORKDIR" \
+    echo "WARNING: could not pre-trust workdir for claude agent $AGENT_NAME" >&2
-      || echo "WARNING: could not pre-trust workdir for claude agent $AGENT_NAME" >&2
+fi
-    ;;
-esac
 
-# ── Launch the tmux session (no exec — we continue to wire the heartbeat) ────
+LAUNCH_COMMAND=(mosaic yolo "$MOSAIC_AGENT_RUNTIME")
+if [ -n "$MOSAIC_AGENT_MODEL" ]; then LAUNCH_COMMAND+=(--model "$MOSAIC_AGENT_MODEL"); fi
+if [ -n "$MOSAIC_AGENT_REASONING" ]; then LAUNCH_COMMAND+=(--thinking "$MOSAIC_AGENT_REASONING"); fi
+
+# The tmux holder owns a named server. Explicitly clear the pane environment
+# so server/session variables cannot cross the launch boundary; retain only
+# trusted bootstrap, generated, and approved local data as argv assignments.
+LAUNCH_ENV=(
+  /usr/bin/env
+  -i
+  "HOME=$PANE_HOME"
+  "PATH=$PANE_PATH"
+  "MOSAIC_HOME=$MOSAIC_HOME"
+  "MOSAIC_AGENT_NAME=$AGENT_NAME"
+  "MOSAIC_AGENT_CLASS=$MOSAIC_AGENT_CLASS"
+  "MOSAIC_AGENT_RUNTIME=$MOSAIC_AGENT_RUNTIME"
+  "MOSAIC_AGENT_MODEL=$MOSAIC_AGENT_MODEL"
+  "MOSAIC_AGENT_REASONING=$MOSAIC_AGENT_REASONING"
+  "MOSAIC_AGENT_TOOL_POLICY=$MOSAIC_AGENT_TOOL_POLICY"
+  "MOSAIC_AGENT_WORKDIR=$MOSAIC_AGENT_WORKDIR"
+  "MOSAIC_TMUX_SOCKET=$MOSAIC_TMUX_SOCKET"
+  "MOSAIC_HEARTBEAT_RUN_DIR=$MOSAIC_HEARTBEAT_RUN_DIR"
+)
+
+mkdir -p "$MOSAIC_AGENT_WORKDIR"
 _tmux new-session -d -s "$AGENT_NAME" -c "$MOSAIC_AGENT_WORKDIR" \
-  bash -c "$PANE_SHELL_SNIPPET"
+  "${LAUNCH_ENV[@]}" "${LAUNCH_COMMAND[@]}"
 
-# ── Resolve the pane PID (retry briefly to let the session initialise) ────────
 PANE_PID=""
 for _retry in 1 2 3 4 5; do
-  PANE_PID=$(_tmux list-panes \
+  PANE_PID=$(_tmux list-panes -t "=${AGENT_NAME}:0.0" -F '#{pane_pid}' 2>/dev/null || true)
-    -t "=${AGENT_NAME}:0.0" -F '#{pane_pid}' 2>/dev/null || true)
   [ -n "$PANE_PID" ] && break
   sleep 0.2
 done
 
-# ── Spawn the heartbeat sidecar (detached, best-effort) ──────────────────────
-# The sidecar writes ~/.config/mosaic/fleet/run/<AGENT>.hb atomically while the
-# pane process is alive, then exits so the file goes stale (fleet ps shows stale
-# then PANE=dead).  It is runtime-agnostic: it only cares about the pane PID.
 _start_heartbeat_sidecar() {
-  local agent="$1"
+  local agent="$1" pane_pid="$2" run_dir="$3" interval="$4"
-  local pane_pid="$2"
-  local run_dir="$3"
-  local interval="$4"
   local hb_file="${run_dir}/${agent}.hb"
-
   mkdir -p "$run_dir"
-
-  # Write the sidecar as a self-contained bash one-liner so it carries no
-  # references to any variables from this script's environment.
   local sidecar_script
   sidecar_script=$(printf \
-    'hb=%q; pid=%q; iv=%q; mkdir -p "$(dirname "$hb")"; while kill -0 "$pid" 2>/dev/null; do nat="$hb.native"; if [ -f "$nat" ] && [ "$(( $(date +%%s) - $(stat -c %%Y "$nat" 2>/dev/null || echo 0) ))" -lt "$(( iv * 2 ))" ]; then sleep "$iv"; continue; fi; tmp="$hb.tmp.$$"; printf "ts=%%s\npid=%%s\nstatus=ok\n" "$(date +%%Y-%%m-%%dT%%H:%%M:%%S%%z)" "$pid" > "$tmp" && mv "$tmp" "$hb"; sleep "$iv"; done' \
+    'hb=%q; pid=%q; iv=%q; native="$hb.native"; mkdir -p "$(dirname "$hb")"; while kill -0 "$pid" 2>/dev/null; do now=$(date +%%s); marker=$(stat -c %%Y -- "$native" 2>/dev/null || true); if [ -z "$marker" ] || [ -L "$native" ] || (( now - marker > iv * 2 + 1 )); then tmp="$hb.tmp.$$"; printf "ts=%%s\npid=%%s\nstatus=ok\n" "$(date +%%Y-%%m-%%dT%%H:%%M:%%S%%z)" "$pid" > "$tmp" && mv "$tmp" "$hb"; fi; sleep "$iv"; done' \
     "$hb_file" "$pane_pid" "$interval")
-
-  # setsid + disown ensures the sidecar survives this script exiting.
-  # stderr/stdout go to /dev/null; failures are non-fatal.
   if command -v setsid >/dev/null 2>&1; then
     setsid bash -c "$sidecar_script" </dev/null >/dev/null 2>&1 &
   else
@@ -266,7 +381,6 @@ _start_heartbeat_sidecar() {
 }
 
 if [ -n "$PANE_PID" ]; then
-  # Guard: do not let sidecar startup failures abort the launcher (set -e).
   _start_heartbeat_sidecar "$AGENT_NAME" "$PANE_PID" \
     "$MOSAIC_HEARTBEAT_RUN_DIR" "$MOSAIC_HEARTBEAT_INTERVAL" || \
     echo "WARNING: heartbeat sidecar could not be started for $AGENT_NAME" >&2

packages/mosaic/framework/tools/fleet/start-interaction-service.sh

@@ -9,11 +9,7 @@ fail() {
 }
 
 [ -n "$AGENT_NAME" ] || fail "agent name argument is required"
-[[ "$AGENT_NAME" =~ ^[A-Za-z0-9_.-]+$ ]] || fail "agent name contains unsupported characters"
-[ "${MOSAIC_AGENT_NAME:-}" = "$AGENT_NAME" ] || fail "configured agent name must exactly match the service instance"
-[ "${MOSAIC_AGENT_RUNTIME:-}" = "pi" ] || fail "operator interaction service requires runtime pi"
-[ "${MOSAIC_AGENT_MODEL:-}" = "openai/gpt-5.6-sol" ] || fail "operator interaction service requires the pinned model"
-[ "${MOSAIC_AGENT_REASONING:-}" = "high" ] || fail "operator interaction service requires high reasoning"
-[ "${MOSAIC_AGENT_TOOL_POLICY:-}" = "operator-interaction" ] || fail "operator interaction service requires the operator-interaction tool policy"
 
-exec "$(cd -- "$(dirname -- "$0")" && pwd)/start-agent-session.sh" "$AGENT_NAME"
+# The shared launcher strictly validates the generated/local data boundary
+# before it applies this interaction service's pinned profile checks.
+exec "$(cd -- "$(dirname -- "$0")" && pwd)/start-agent-session.sh" --interaction "$AGENT_NAME"

packages/mosaic/framework/tools/fleet/start-tmux-holder.sh

@@ -0,0 +1,64 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# A holder may create only the configured named socket. Existing servers are
+# accepted only when their private install-derived ownership identity, exact
+# holder session, and complete approved global environment all match.
+
+MOSAIC_HOME=${MOSAIC_HOME:-$HOME/.config/mosaic}
+MOSAIC_TMUX_SOCKET=${MOSAIC_TMUX_SOCKET:-mosaic-fleet}
+MOSAIC_TMUX_HOLDER=${MOSAIC_TMUX_HOLDER:-_holder}
+OWNER_FILE="$MOSAIC_HOME/fleet/run/holder-owner"
+TMUX_BIN=/usr/bin/tmux
+
+fail() {
+  echo "ERROR: refusing unmanaged Mosaic tmux server on socket ${MOSAIC_TMUX_SOCKET}: $1" >&2
+  exit 64
+}
+
+[ -x "$TMUX_BIN" ] || fail "tmux binary is unavailable"
+[ -f "$OWNER_FILE" ] && [ ! -L "$OWNER_FILE" ] || fail "private ownership identity is missing"
+owner_mode=$(stat -c '%a' -- "$OWNER_FILE") || fail "private ownership identity is unreadable"
+(( (8#$owner_mode & 8#077) == 0 )) || fail "private ownership identity has unsafe permissions"
+MOSAIC_FLEET_OWNER=$(tr -d '\n' < "$OWNER_FILE")
+[[ "$MOSAIC_FLEET_OWNER" =~ ^[a-f0-9-]{36}$ ]] || fail "private ownership identity is malformed"
+
+_tmux() {
+  "$TMUX_BIN" -L "$MOSAIC_TMUX_SOCKET" "$@"
+}
+
+server_running() {
+  _tmux list-sessions >/dev/null 2>&1
+}
+
+assert_owned_server() {
+  _tmux has-session -t "=${MOSAIC_TMUX_HOLDER}:0.0" 2>/dev/null || fail "exact holder session is absent"
+  local environment
+  environment=$(_tmux show-environment -g 2>/dev/null) || fail "global environment is unreadable"
+  local expected
+  expected=$(printf '%s\n' \
+    "HOME=$HOME" \
+    'PATH=/usr/bin:/bin' \
+    "PWD=$HOME" \
+    "MOSAIC_FLEET_OWNER=$MOSAIC_FLEET_OWNER" \
+    "MOSAIC_TMUX_HOLDER=$MOSAIC_TMUX_HOLDER" \
+    "MOSAIC_TMUX_SOCKET=$MOSAIC_TMUX_SOCKET" | sort)
+  [ "$(printf '%s\n' "$environment" | sort)" = "$expected" ] || \
+    fail "global environment does not match the owned-server contract"
+}
+
+if server_running; then
+  assert_owned_server
+else
+  cd "$HOME" || fail "trusted home is unavailable"
+  # Start the tmux server itself under the approved environment. The holder pane
+  # receives the same closed environment rather than arbitrary server globals.
+  /usr/bin/env -i \
+    "HOME=$HOME" \
+    PATH=/usr/bin:/bin \
+    "MOSAIC_FLEET_OWNER=$MOSAIC_FLEET_OWNER" \
+    "MOSAIC_TMUX_HOLDER=$MOSAIC_TMUX_HOLDER" \
+    "MOSAIC_TMUX_SOCKET=$MOSAIC_TMUX_SOCKET" \
+    "$TMUX_BIN" -L "$MOSAIC_TMUX_SOCKET" new-session -d -s "$MOSAIC_TMUX_HOLDER" \
+    /usr/bin/env -i "HOME=$HOME" PATH=/usr/bin:/bin /bin/sh -c 'while true; do sleep 3600; done'
+fi

packages/mosaic/framework/tools/fleet/test-start-agent-session.sh

@@ -3,373 +3,410 @@ set -euo pipefail
 
 SCRIPT_DIR=$(cd -- "$(dirname -- "$0")" && pwd)
 START="$SCRIPT_DIR/start-agent-session.sh"
-SOCKET="mosaic-agent-test-$RANDOM-$$"
+INTERACTION_START="$SCRIPT_DIR/start-interaction-service.sh"
-AGENT="agent-$RANDOM"
+ROOT=$(mktemp -d)
-WORKDIR=$(mktemp -d)
+FAKE_BIN=$(mktemp -d)
-
+TMUX_CALLS=$(mktemp)
-# Keep a single cleanup trap that accumulates resources.
+trap 'rm -rf "$ROOT" "$FAKE_BIN" "$TMUX_CALLS"' EXIT
-CLEANUP_DIRS=("$WORKDIR")
-CLEANUP_SOCKETS=("$SOCKET")
-trap '_cleanup' EXIT
-_cleanup() {
-  for s in "${CLEANUP_SOCKETS[@]:-}"; do
-    tmux -L "$s" kill-server >/dev/null 2>&1 || true
-  done
-  for d in "${CLEANUP_DIRS[@]:-}"; do
-    rm -rf "$d"
-  done
-}
 
 fail() {
   echo "FAIL: $*" >&2
   exit 1
 }
 
-# ── Test 1: basic session creation with workdir check ─────────────────────────
+cat > "$FAKE_BIN/tmux" <<'SHIM'
-MOSAIC_TMUX_SOCKET="$SOCKET" \
-MOSAIC_AGENT_WORKDIR="$WORKDIR" \
-MOSAIC_AGENT_COMMAND='bash --noprofile --norc -i' \
-  "$START" "$AGENT"
-
-tmux -L "$SOCKET" has-session -t "=$AGENT:0.0" || fail "agent session was not created"
-# Retry: pane_current_path briefly reflects the tmux server's cwd until the pane
-# process establishes its own cwd (the -c start dir). Poll until it settles.
-actual_dir=""
-for _ in $(seq 1 30); do
-  actual_dir=$(tmux -L "$SOCKET" display-message -p -t "=$AGENT:0.0" '#{pane_current_path}')
-  [ "$actual_dir" = "$WORKDIR" ] && break
-  sleep 0.1
-done
-[ "$actual_dir" = "$WORKDIR" ] || fail "agent workdir mismatch: $actual_dir (expected $WORKDIR)"
-
-# ── Test 2: idempotency (duplicate start prints 'already running') ─────────────
-MOSAIC_TMUX_SOCKET="$SOCKET" \
-MOSAIC_AGENT_WORKDIR="$WORKDIR" \
-MOSAIC_AGENT_COMMAND='bash --noprofile --norc -i' \
-  "$START" "$AGENT" >/tmp/mosaic-start-agent-idempotent.out
-
-grep -qF 'already running' /tmp/mosaic-start-agent-idempotent.out || fail "duplicate start was not idempotent"
-
-# ── Test 3: runtime-bin PATH prefix is baked into the pane command ────────────
-#
-# We capture the command the script would hand to tmux by injecting a fake
-# 'tmux' shim into PATH.  The shim:
-#   - Intercepts 'new-session' calls and records its arguments to a file.
-#   - For 'has-session' calls, exits 1 (session does not exist) so the script
-#     proceeds to launch instead of printing "already running".
-#   - For 'list-panes' calls, returns empty so PANE_PID stays unset and the
-#     heartbeat sidecar is NOT spawned (heartbeat is not the focus of this test;
-#     test 6 and 7 cover that path).  This prevents any real-filesystem side
-#     effects or leaked background processes.
-#   - For all other subcommands, exits 0.
-#
-# Assertions:
-#   a) 'export PATH=' with the synthetic MOSAIC_RUNTIME_BIN prefix appears.
-#   b) 'exec' appears so the runtime replaces the wrapper shell.
-#   c) MOSAIC_AGENT_COMMAND with flags is forwarded intact.
-
-FAKE_BIN=$(mktemp -d)
-FAKE_RUNTIME_BIN=$(mktemp -d)
-TMUX_ARGS_FILE=$(mktemp)
-HB_RUN_DIR3=$(mktemp -d)
-CLEANUP_DIRS+=("$FAKE_BIN" "$FAKE_RUNTIME_BIN" "$HB_RUN_DIR3")
-
-# Write the fake tmux shim (uses only positional args, no sourced vars).
-cat > "$FAKE_BIN/tmux" <<SHIM
 #!/usr/bin/env bash
-# Fake tmux: record new-session args; report has-session as missing.
+set -euo pipefail
-subcmd="\$3"  # argv: tmux -L <socket> <subcmd> ...
+printf '%s\0' "$@" >> "${MOSAIC_TEST_TMUX_CALLS:?}"
-if [ "\$subcmd" = "has-session" ]; then
+args=("$@")
-  exit 1   # session not found → script will attempt new-session
+index=0
-fi
+if [ "${args[0]:-}" = -L ]; then index=2; fi
-if [ "\$subcmd" = "new-session" ]; then
+case "${args[$index]:-}" in
-  printf '%s\n' "\$@" > "$TMUX_ARGS_FILE"
+  has-session)
-  exit 0
+    for argument in "${args[@]}"; do
-fi
+      [ "$argument" = '=_holder:0.0' ] && exit 0
-if [ "\$subcmd" = "list-panes" ]; then
+    done
-  # Return empty: no sidecar spawned (heartbeat is not the focus of this test).
+    exit 1
-  echo ""
+    ;;
-  exit 0
+  show-environment)
-fi
+    printf '%s\n' \
-exit 0
+      "HOME=${MOSAIC_TEST_HOME:?}" \
+      'PATH=/usr/bin:/bin' \
+      "PWD=${MOSAIC_TEST_HOME:?}" \
+      "MOSAIC_FLEET_OWNER=${MOSAIC_TEST_FLEET_OWNER:?}" \
+      'MOSAIC_TMUX_HOLDER=_holder' \
+      'MOSAIC_TMUX_SOCKET=mosaic-test'
+    exit 0
+    ;;
+  list-panes) printf '%s\n' "${MOSAIC_TEST_PANE_PID:-}"; exit 0 ;;
+  new-session)
+    if [ "${MOSAIC_TEST_EXECUTE_PANE:-}" = 1 ]; then
+      for ((index = 0; index < ${#args[@]}; index++)); do
+        if [ "${args[$index]}" = /usr/bin/env ]; then
+          "${args[@]:$index}"
+          break
+        fi
+      done
+    fi
+    exit 0
+    ;;
+  *) exit 0 ;;
+esac
 SHIM
 chmod +x "$FAKE_BIN/tmux"
 
-SOCKET3="mosaic-agent-test3-$RANDOM-$$"
+cat > "$FAKE_BIN/mosaic" <<'SHIM'
-AGENT3="agent3-$RANDOM"
-WORKDIR3=$(mktemp -d)
-CLEANUP_DIRS+=("$WORKDIR3")
-
-PATH="$FAKE_BIN:$PATH" \
-MOSAIC_TMUX_SOCKET="$SOCKET3" \
-MOSAIC_AGENT_WORKDIR="$WORKDIR3" \
-MOSAIC_AGENT_RUNTIME="pi" \
-MOSAIC_AGENT_CLASS="code" \
-MOSAIC_AGENT_TOOL_POLICY="operator-interaction" \
-MOSAIC_RUNTIME_BIN="$FAKE_RUNTIME_BIN" \
-MOSAIC_AGENT_COMMAND="mosaic yolo pi --model openai-codex/gpt-5.5:high" \
-MOSAIC_HEARTBEAT_RUN_DIR="$HB_RUN_DIR3" \
-  "$START" "$AGENT3"
-
-all_args=$(cat "$TMUX_ARGS_FILE" 2>/dev/null || true)
-rm -f "$TMUX_ARGS_FILE"
-
-echo "--- captured tmux new-session args ---"
-echo "$all_args"
-echo "--- end args ---"
-
-# a) PATH prefix containing FAKE_RUNTIME_BIN must appear.
-echo "$all_args" | grep -qF "export PATH=" || fail "pane command does not export PATH"
-echo "$all_args" | grep -qF "$FAKE_RUNTIME_BIN" || fail "pane command does not include MOSAIC_RUNTIME_BIN in PATH prefix"
-
-# b) exec must appear so the runtime replaces the wrapper shell.
-echo "$all_args" | grep -qF "exec " || fail "pane command does not use exec"
-
-# c) Full MOSAIC_AGENT_COMMAND (with flags) must be forwarded.
-echo "$all_args" | grep -qF "mosaic yolo pi --model openai-codex/gpt-5.5:high" || \
-  fail "pane command does not forward MOSAIC_AGENT_COMMAND with flags intact"
-
-# d) MOSAIC_AGENT_NAME and the per-agent MOSAIC_AGENT_CLASS must BOTH be exported
-#    INTO the pane. The pane inherits the tmux SERVER environment (not this
-#    script's env, nor the systemd unit's EnvironmentFile), so any per-agent var
-#    the launcher needs in-pane must be re-exported in the snippet. CLASS is
-#    load-bearing: the launcher composes the persona contract from
-#    process.env.MOSAIC_AGENT_CLASS, so a missing export silently drops the
-#    persona (regression guard for the A3a pane-propagation gap).
-echo "$all_args" | grep -qF "export MOSAIC_AGENT_NAME=" || \
-  fail "pane command does not export MOSAIC_AGENT_NAME into the pane"
-echo "$all_args" | grep -qF "export MOSAIC_AGENT_CLASS=code" || \
-  fail "pane command does not export MOSAIC_AGENT_CLASS into the pane (persona would silently drop)"
-echo "$all_args" | grep -qF "export MOSAIC_AGENT_TOOL_POLICY=operator-interaction" || \
-  fail "pane command does not export MOSAIC_AGENT_TOOL_POLICY into the pane"
-
-# ── Test 4: when no extra runtime-bin dirs exist, exec still appears ───────────
-TMUX_ARGS_FILE2=$(mktemp)
-FAKE_BIN2=$(mktemp -d)
-HB_RUN_DIR4=$(mktemp -d)
-CLEANUP_DIRS+=("$FAKE_BIN2" "$HB_RUN_DIR4")
-
-cat > "$FAKE_BIN2/tmux" <<SHIM2
 #!/usr/bin/env bash
-subcmd="\$3"
+set -euo pipefail
-if [ "\$subcmd" = "has-session" ]; then exit 1; fi
+env -0 > "${MOSAIC_HOME:?}/fleet/pane-environment"
-if [ "\$subcmd" = "new-session" ]; then
+SHIM
-  printf '%s\n' "\$@" > "$TMUX_ARGS_FILE2"
+chmod +x "$FAKE_BIN/mosaic"
-  exit 0
+
+write_generated() {
+  local home="$1"
+  local agent="$2"
+  mkdir -p "$home/fleet/agents" "$home/fleet/run"
+  chmod 700 "$home" "$home/fleet" "$home/fleet/agents" "$home/fleet/run"
+  printf '123e4567-e89b-12d3-a456-426614174000\n' > "$home/fleet/run/holder-owner"
+  chmod 600 "$home/fleet/run/holder-owner"
+  cat > "$home/fleet/agents/$agent.env.generated" <<EOF
+MOSAIC_AGENT_NAME=$agent
+MOSAIC_AGENT_CLASS=code
+MOSAIC_AGENT_RUNTIME=pi
+MOSAIC_AGENT_MODEL=openai-codex/gpt-5.6-sol
+MOSAIC_AGENT_REASONING=high
+MOSAIC_AGENT_TOOL_POLICY=code
+MOSAIC_AGENT_WORKDIR=$home/work
+MOSAIC_TMUX_SOCKET=mosaic-test
+EOF
+  chmod 600 "$home/fleet/agents/$agent.env.generated"
+  mkdir -p "$home/work"
+}
+
+run_start() {
+  local home="$1"
+  local agent="$2"
+  HOME="$home" PATH="$FAKE_BIN:$PATH" MOSAIC_TEST_TMUX_CALLS="$TMUX_CALLS" \
+    MOSAIC_TEST_PANE_PID="${MOSAIC_TEST_PANE_PID:-}" \
+    MOSAIC_TEST_HOME="$home" \
+    MOSAIC_TEST_FLEET_OWNER=123e4567-e89b-12d3-a456-426614174000 \
+    MOSAIC_HOME="$home" "$START" "$agent"
+}
+
+# Valid generated data launches only the fixed runtime argument array. It never
+# reads an agent-command string or constructs a bash -c pane payload.
+HOME_VALID="$ROOT/valid"
+AGENT_VALID="coder0"
+write_generated "$HOME_VALID" "$AGENT_VALID"
+run_start "$HOME_VALID" "$AGENT_VALID"
+valid_args=$(tr '\0' '\n' < "$TMUX_CALLS")
+echo "$valid_args" | grep -qF new-session || fail "valid generated projection did not reach tmux"
+echo "$valid_args" | grep -qF 'mosaic' || fail "fixed mosaic launcher command missing"
+echo "$valid_args" | grep -qF 'yolo' || fail "fixed yolo launcher command missing"
+echo "$valid_args" | grep -qF 'pi' || fail "roster runtime missing"
+if echo "$valid_args" | grep -qF 'bash -c'; then
+  fail "launcher constructed a shell command payload"
 fi
-if [ "\$subcmd" = "list-panes" ]; then
+
-  # Return empty: no sidecar spawned (heartbeat is not the focus of this test).
+# The pane must start through an absolute clean-environment boundary. Its
-  echo ""
+# runtime command remains an argv vector, but no holder/session environment
-  exit 0
+# control variable can pass through the pane command.
+echo "$valid_args" | grep -qxF '/usr/bin/env' || fail "pane does not use absolute env"
+echo "$valid_args" | grep -qxF -- '-i' || fail "pane environment is not cleared"
+
+# The generated-file parent is a security boundary too: even a private regular
+# file is untrusted if its parent can be replaced or written by another user.
+# Validation must happen before fake tmux receives even a has-session call.
+: > "$TMUX_CALLS"
+HOME_UNSAFE_PARENT="$ROOT/unsafe-parent"
+write_generated "$HOME_UNSAFE_PARENT" "coder-parent"
+chmod 777 "$HOME_UNSAFE_PARENT/fleet/agents"
+if output=$(run_start "$HOME_UNSAFE_PARENT" coder-parent 2>&1); then
+  fail "generated file under a world-writable parent was accepted"
 fi
-exit 0
+[ ! -s "$TMUX_CALLS" ] || fail "tmux ran before unsafe parent rejection"
-SHIM2
+echo "$output" | grep -qF 'code=unsafe-permissions' || fail "unsafe parent diagnostic missing"
-chmod +x "$FAKE_BIN2/tmux"
 
-SOCKET4="mosaic-agent-test4-$RANDOM-$$"
+: > "$TMUX_CALLS"
-AGENT4="agent4-$RANDOM"
+HOME_SYMLINK_PARENT="$ROOT/symlink-parent"
-WORKDIR4=$(mktemp -d)
+write_generated "$HOME_SYMLINK_PARENT" "coder-symlink-parent"
-CLEANUP_DIRS+=("$WORKDIR4")
+mv "$HOME_SYMLINK_PARENT/fleet/agents" "$HOME_SYMLINK_PARENT/private-agents"
-
+ln -s "$HOME_SYMLINK_PARENT/private-agents" "$HOME_SYMLINK_PARENT/fleet/agents"
-# MOSAIC_RUNTIME_BIN points to a non-existent dir so prefix will be empty;
+if output=$(run_start "$HOME_SYMLINK_PARENT" coder-symlink-parent 2>&1); then
-# .npm-global/bin and .local/bin may or may not exist but we just want exec.
+  fail "generated file under a symlinked parent was accepted"
-PATH="$FAKE_BIN2:$PATH" \
-MOSAIC_TMUX_SOCKET="$SOCKET4" \
-MOSAIC_AGENT_WORKDIR="$WORKDIR4" \
-MOSAIC_AGENT_RUNTIME="pi" \
-MOSAIC_RUNTIME_BIN="/nonexistent-dir-$$" \
-MOSAIC_AGENT_COMMAND="mosaic yolo pi" \
-MOSAIC_HEARTBEAT_RUN_DIR="$HB_RUN_DIR4" \
-  "$START" "$AGENT4"
-
-all_args4=$(cat "$TMUX_ARGS_FILE2" 2>/dev/null || true)
-rm -f "$TMUX_ARGS_FILE2"
-rm -rf "$WORKDIR4"
-
-echo "$all_args4" | grep -qF "exec " || fail "pane command (no prefix dirs) does not use exec"
-echo "$all_args4" | grep -qF "mosaic yolo pi" || fail "pane command does not include agent command when no prefix"
-
-# ── Test 5: candidate dir already in LAUNCHER $PATH is still baked into pane ──
-#
-# Regression guard for the bug where _build_runtime_bin_prefix() used to skip
-# a candidate because it was already present in the launcher process's $PATH.
-# That check was wrong: the pane inherits the tmux SERVER environment, not the
-# launcher's env.  Even if a dir is on the launcher's PATH it must always be
-# baked into the pane's PATH export.
-#
-# We prove this by setting PATH to include FAKE_RUNTIME_BIN5 (the candidate),
-# then asserting the generated new-session command still exports it.
-TMUX_ARGS_FILE5=$(mktemp)
-FAKE_BIN5=$(mktemp -d)
-FAKE_RUNTIME_BIN5=$(mktemp -d)  # this dir IS on the launcher's PATH below
-HB_RUN_DIR5=$(mktemp -d)
-CLEANUP_DIRS+=("$FAKE_BIN5" "$FAKE_RUNTIME_BIN5" "$HB_RUN_DIR5")
-
-cat > "$FAKE_BIN5/tmux" <<SHIM5
-#!/usr/bin/env bash
-subcmd="\$3"
-if [ "\$subcmd" = "has-session" ]; then exit 1; fi
-if [ "\$subcmd" = "new-session" ]; then
-  printf '%s\n' "\$@" > "$TMUX_ARGS_FILE5"
-  exit 0
 fi
-if [ "\$subcmd" = "list-panes" ]; then
+[ ! -s "$TMUX_CALLS" ] || fail "tmux ran before symlinked parent rejection"
-  # Return empty: no sidecar spawned (heartbeat is not the focus of this test).
+echo "$output" | grep -qF 'code=unsafe-directory' || fail "symlinked parent diagnostic missing"
-  echo ""
-  exit 0
-fi
-exit 0
-SHIM5
-chmod +x "$FAKE_BIN5/tmux"
 
-SOCKET5="mosaic-agent-test5-$RANDOM-$$"
+# Every managed ancestor is a boundary: MOSAIC_HOME, fleet, and agents. A
-AGENT5="agent5-$RANDOM"
+# symlink or group/world-writable ancestor must fail before environment parsing,
-WORKDIR5=$(mktemp -d)
+# workdir creation, or tmux effects. The malformed local input proves parsing
-CLEANUP_DIRS+=("$WORKDIR5")
+# was not reached when the ancestor rejection is reported.
-CLEANUP_SOCKETS+=("$SOCKET5")
+assert_managed_ancestor_rejected() {
+  local ancestor="$1"
+  local hazard="$2"
+  local home="$ROOT/managed-${ancestor//\//-}-${hazard}"
+  local agent="coder-managed-${ancestor//\//-}-${hazard}"
+  local node
+  write_generated "$home" "$agent"
+  printf 'MOSAIC_AGENT_COMMAND=must-not-be-parsed\n' > "$home/fleet/agents/$agent.env.local"
+  chmod 600 "$home/fleet/agents/$agent.env.local"
+  rm -rf "$home/work"
 
-# FAKE_RUNTIME_BIN5 is deliberately placed on the LAUNCHER PATH so that the
+  case "$ancestor" in
-# old (buggy) code would have skipped it.  The correct code must still include
+    MOSAIC_HOME) node="$home" ;;
-# it in the pane PATH export.
+    MOSAIC_HOME/fleet) node="$home/fleet" ;;
-PATH="$FAKE_BIN5:$FAKE_RUNTIME_BIN5:$PATH" \
+    MOSAIC_HOME/fleet/agents) node="$home/fleet/agents" ;;
-MOSAIC_TMUX_SOCKET="$SOCKET5" \
+    *) fail "unknown managed ancestor: $ancestor" ;;
-MOSAIC_AGENT_WORKDIR="$WORKDIR5" \
+  esac
-MOSAIC_AGENT_RUNTIME="pi" \
-MOSAIC_RUNTIME_BIN="$FAKE_RUNTIME_BIN5" \
-MOSAIC_AGENT_COMMAND="mosaic yolo pi" \
-MOSAIC_HEARTBEAT_RUN_DIR="$HB_RUN_DIR5" \
-  "$START" "$AGENT5"
 
-all_args5=$(cat "$TMUX_ARGS_FILE5" 2>/dev/null || true)
+  if [ "$hazard" = symlink ]; then
-rm -f "$TMUX_ARGS_FILE5"
+    local target="${node}-target"
-rm -rf "$WORKDIR5"
+    mv "$node" "$target"
+    ln -s "$target" "$node"
+  else
+    chmod 777 "$node"
+  fi
 
-echo "--- test 5: launcher-PATH candidate must still appear in pane export ---"
+  : > "$TMUX_CALLS"
-echo "$all_args5"
+  if output=$(run_start "$home" "$agent" 2>&1); then
-echo "--- end test 5 args ---"
+    fail "${hazard} $ancestor was accepted"
+  fi
+  [ ! -s "$TMUX_CALLS" ] || fail "tmux ran before $hazard $ancestor rejection"
+  [ ! -e "$home/work" ] || fail "workdir was created before $hazard $ancestor rejection"
+  echo "$output" | grep -qF "code=unsafe-" || fail "managed ancestor diagnostic missing"
+  if echo "$output" | grep -qF 'key=MOSAIC_AGENT_COMMAND'; then
+    fail "environment parsing ran before $hazard $ancestor rejection"
+  fi
+}
 
-echo "$all_args5" | grep -qF "export PATH=" || \
+for managed_ancestor in MOSAIC_HOME MOSAIC_HOME/fleet MOSAIC_HOME/fleet/agents; do
-  fail "test5: pane command does not export PATH when candidate is on launcher PATH"
+  assert_managed_ancestor_rejected "$managed_ancestor" symlink
-echo "$all_args5" | grep -qF "$FAKE_RUNTIME_BIN5" || \
+  assert_managed_ancestor_rejected "$managed_ancestor" group-world-writable
-  fail "test5: candidate dir (already on launcher PATH) was NOT baked into pane PATH — regression"
-
-# ── Test 6: heartbeat sidecar — pane PID resolved + .hb file written ──────────
-#
-# Uses a real tmux session (same socket as test 1 which already has $AGENT) so
-# list-panes returns a real pane PID.  We override MOSAIC_HEARTBEAT_RUN_DIR to
-# a temp dir and set a 1-second interval, then wait up to 3 s for the .hb file
-# to appear and check its content.
-
-HB_RUN_DIR=$(mktemp -d)
-CLEANUP_DIRS+=("$HB_RUN_DIR")
-
-# Re-use the session+agent created in Test 1 (still alive on $SOCKET / $AGENT).
-# We need to invoke the script for a NEW agent on the same socket to exercise
-# the heartbeat path with a real pane PID.
-AGENT6="agent6-$RANDOM"
-MOSAIC_TMUX_SOCKET="$SOCKET" \
-MOSAIC_AGENT_WORKDIR="$WORKDIR" \
-MOSAIC_AGENT_COMMAND='bash --noprofile --norc -i' \
-MOSAIC_HEARTBEAT_RUN_DIR="$HB_RUN_DIR" \
-MOSAIC_HEARTBEAT_INTERVAL="1" \
-  "$START" "$AGENT6"
-
-HB_FILE="$HB_RUN_DIR/${AGENT6}.hb"
-
-# Wait up to 5 seconds for the heartbeat file to appear.
-_waited=0
-until [ -f "$HB_FILE" ] || [ "$_waited" -ge 5 ]; do
-  sleep 0.5
-  _waited=$((_waited + 1))
 done
 
-[ -f "$HB_FILE" ] || fail "test6: heartbeat file not written at $HB_FILE within 5s"
+# A local file cannot shadow any roster-derived generated key. Validation must
+# happen before fake tmux receives even a has-session call.
+: > "$TMUX_CALLS"
+HOME_SHADOW="$ROOT/shadow"
+write_generated "$HOME_SHADOW" "coder1"
+printf 'MOSAIC_AGENT_RUNTIME=codex\n' > "$HOME_SHADOW/fleet/agents/coder1.env.local"
+chmod 600 "$HOME_SHADOW/fleet/agents/coder1.env.local"
+if output=$(run_start "$HOME_SHADOW" coder1 2>&1); then
+  fail "generated-key shadow was accepted"
+fi
+[ ! -s "$TMUX_CALLS" ] || fail "tmux ran before generated-key shadow rejection"
+echo "$output" | grep -qF 'key=MOSAIC_AGENT_RUNTIME' || fail "shadow diagnostic omitted key"
+echo "$output" | grep -qF 'sha256=' || fail "shadow diagnostic omitted hash"
+if echo "$output" | grep -qF 'codex'; then
+  fail "shadow diagnostic leaked value"
+fi
 
-hb_content=$(cat "$HB_FILE")
+# Arbitrary command compatibility is quarantined/rejected as data. Diagnostics
-echo "--- test 6: heartbeat file content ---"
+# may name the key and hash but must never echo the privileged command text.
-echo "$hb_content"
+: > "$TMUX_CALLS"
-echo "--- end test 6 ---"
+HOME_COMMAND="$ROOT/command"
+write_generated "$HOME_COMMAND" "coder2"
+COMMAND_VALUE='mosaic yolo codex --dangerous'
+printf 'MOSAIC_AGENT_COMMAND=%s\n' "$COMMAND_VALUE" > "$HOME_COMMAND/fleet/agents/coder2.env.local"
+chmod 600 "$HOME_COMMAND/fleet/agents/coder2.env.local"
+if output=$(run_start "$HOME_COMMAND" coder2 2>&1); then
+  fail "arbitrary command override was accepted"
+fi
+[ ! -s "$TMUX_CALLS" ] || fail "tmux ran before command rejection"
+echo "$output" | grep -qF 'key=MOSAIC_AGENT_COMMAND' || fail "command diagnostic omitted key"
+echo "$output" | grep -qF 'sha256=' || fail "command diagnostic omitted hash"
+if echo "$output" | grep -qF "$COMMAND_VALUE"; then
+  fail "command diagnostic leaked command value"
+fi
 
-# Verify required fields are present.
+# Group/world-readable local input is not trusted even when its syntax is safe.
-echo "$hb_content" | grep -qE '^ts=[0-9]{4}-[0-9]{2}-[0-9]{2}T' || \
+: > "$TMUX_CALLS"
-  fail "test6: heartbeat ts field missing or malformed"
+HOME_PERMS="$ROOT/perms"
-echo "$hb_content" | grep -qE '^pid=[0-9]+' || \
+write_generated "$HOME_PERMS" "coder3"
-  fail "test6: heartbeat pid field missing or malformed"
+printf 'MOSAIC_RUNTIME_BIN=/opt/mosaic/bin\n' > "$HOME_PERMS/fleet/agents/coder3.env.local"
-echo "$hb_content" | grep -qF 'status=ok' || \
+chmod 644 "$HOME_PERMS/fleet/agents/coder3.env.local"
-  fail "test6: heartbeat status=ok missing"
+if output=$(run_start "$HOME_PERMS" coder3 2>&1); then
+  fail "world-readable local input was accepted"
+fi
+[ ! -s "$TMUX_CALLS" ] || fail "tmux ran before permissions rejection"
+echo "$output" | grep -qF 'code=unsafe-permissions' || fail "permission diagnostic missing"
 
-# ── Test 7: heartbeat sidecar — targets correct .hb path per agent name ────────
+# A unit/holder-like clean bootstrap must yield a pane with trusted HOME and
-#
+# computed PATH only. The pane command itself must not carry loader, shell
-# Uses the fake-tmux shim approach (like tests 3-5) to capture the sidecar
+# control, arbitrary sentinel, or stale bootstrap variables.
-# invocation without needing a real session.  A fake setsid shim records its
+: > "$TMUX_CALLS"
-# arguments so we can assert the sidecar script targets the expected .hb path
+HOME_PANE_BOUNDARY="$ROOT/pane-boundary/.config/mosaic"
-# and uses the configured interval.
+write_generated "$HOME_PANE_BOUNDARY" "coder-pane-boundary"
+PANE_TRUSTED_HOME="${HOME_PANE_BOUNDARY%/.config/mosaic}"
+PANE_STALE_HOME="$ROOT/stale-home"
+PANE_STALE_PATH="$ROOT/stale-bin"
+PANE_BASH_ENV="$ROOT/pane-boundary.bash-env"
+printf 'MOSAIC_RUNTIME_BIN=%s\n' "$FAKE_BIN" > \
+  "$HOME_PANE_BOUNDARY/fleet/agents/coder-pane-boundary.env.local"
+chmod 600 "$HOME_PANE_BOUNDARY/fleet/agents/coder-pane-boundary.env.local"
+LD_PRELOAD='/not/loaded/by-clean-bootstrap.so' \
+BASH_ENV="$PANE_BASH_ENV" \
+MOSAIC_UNTRUSTED_SENTINEL='must-not-reach-pane' \
+HOME="$PANE_STALE_HOME" \
+PATH="$PANE_STALE_PATH" \
+  /usr/bin/env -i \
+    "HOME=$PANE_TRUSTED_HOME" \
+    "PATH=$FAKE_BIN:/usr/bin:/bin" \
+    "MOSAIC_HOME=$HOME_PANE_BOUNDARY" \
+    "MOSAIC_TEST_TMUX_CALLS=$TMUX_CALLS" \
+    "MOSAIC_TEST_HOME=$PANE_TRUSTED_HOME" \
+    MOSAIC_TEST_FLEET_OWNER=123e4567-e89b-12d3-a456-426614174000 \
+    MOSAIC_TEST_EXECUTE_PANE=1 \
+    "$START" coder-pane-boundary
+pane_args=$(tr '\0' '\n' < "$TMUX_CALLS")
+echo "$pane_args" | grep -qxF "HOME=$PANE_TRUSTED_HOME" || \
+  fail "pane did not restore trusted HOME"
+echo "$pane_args" | grep -qF "HOME=$PANE_STALE_HOME" && \
+  fail "pane inherited stale HOME"
+echo "$pane_args" | grep -qF "$PANE_STALE_PATH" && fail "pane inherited stale PATH"
+for blocked in LD_PRELOAD= BASH_ENV= MOSAIC_UNTRUSTED_SENTINEL=; do
+  echo "$pane_args" | grep -qF "$blocked" && fail "pane inherited $blocked"
+done
 
-FAKE_BIN7=$(mktemp -d)
+after_pane_env=$(printf '%s\n' "$pane_args" | grep -n -m1 -F '/usr/bin/env' | cut -d: -f1)
-FAKE_RUNTIME_BIN7=$(mktemp -d)
+[ -n "$after_pane_env" ] || fail "pane command did not use absolute env"
-SETSID_ARGS_FILE=$(mktemp)
+printf '%s\n' "$pane_args" | tail -n +"$after_pane_env" | grep -qxF -- '-i' || \
-HB_RUN_DIR7=$(mktemp -d)
+  fail "pane command did not clear its environment"
-CLEANUP_DIRS+=("$FAKE_BIN7" "$FAKE_RUNTIME_BIN7" "$HB_RUN_DIR7")
+pane_environment=$(tr '\0' '\n' < "$HOME_PANE_BOUNDARY/fleet/pane-environment")
+echo "$pane_environment" | grep -qxF "HOME=$PANE_TRUSTED_HOME" || \
+  fail "runtime pane did not receive trusted HOME"
+echo "$pane_environment" | grep -qF "$PANE_STALE_PATH" && fail "runtime pane received stale PATH"
+for blocked in LD_PRELOAD= BASH_ENV= MOSAIC_UNTRUSTED_SENTINEL=; do
+  echo "$pane_environment" | grep -qF "$blocked" && fail "runtime pane received $blocked"
+done
 
-AGENT7="my-fleet-agent-$RANDOM"
+write_interaction_generated() {
-INTERVAL7="42"
+  local home="$1"
+  local agent="$2"
+  mkdir -p "$home/fleet/agents" "$home/fleet/run" "$home/work"
+  chmod 700 "$home" "$home/fleet" "$home/fleet/agents" "$home/fleet/run"
+  printf '123e4567-e89b-12d3-a456-426614174000\n' > "$home/fleet/run/holder-owner"
+  chmod 600 "$home/fleet/run/holder-owner"
+  cat > "$home/fleet/agents/$agent.env.generated" <<EOF
+MOSAIC_AGENT_NAME=$agent
+MOSAIC_AGENT_CLASS=operator-interaction
+MOSAIC_AGENT_RUNTIME=pi
+MOSAIC_AGENT_MODEL=openai/gpt-5.6-sol
+MOSAIC_AGENT_REASONING=high
+MOSAIC_AGENT_TOOL_POLICY=operator-interaction
+MOSAIC_AGENT_WORKDIR=$home/work
+MOSAIC_TMUX_SOCKET=mosaic-test
+EOF
+  chmod 600 "$home/fleet/agents/$agent.env.generated"
+}
 
-# Fake tmux: has-session → not found; new-session → ok; list-panes → known PID.
+run_interaction() {
-cat > "$FAKE_BIN7/tmux" <<SHIM7
+  local home="$1"
-#!/usr/bin/env bash
+  local agent="$2"
-subcmd="\$3"
+  HOME="$home" PATH="$FAKE_BIN:$PATH" MOSAIC_TEST_TMUX_CALLS="$TMUX_CALLS" \
-if [ "\$subcmd" = "has-session" ]; then exit 1; fi
+    MOSAIC_TEST_HOME="$home" \
-if [ "\$subcmd" = "new-session" ]; then exit 0; fi
+    MOSAIC_TEST_FLEET_OWNER=123e4567-e89b-12d3-a456-426614174000 \
-if [ "\$subcmd" = "list-panes" ]; then echo "88888"; exit 0; fi
+    MOSAIC_HOME="$home" "$INTERACTION_START" "$agent"
-exit 0
+}
-SHIM7
-chmod +x "$FAKE_BIN7/tmux"
 
-# Fake setsid: capture the bash -c <script> argument for inspection, then
+write_heartbeat_local() {
-# background an actual bash subshell so disown succeeds in the caller.
+  local home="$1"
-cat > "$FAKE_BIN7/setsid" <<'SETSID_SHIM'
+  local agent="$2"
-#!/usr/bin/env bash
+  mkdir -p "$home/run"
-# argv: setsid bash -c <sidecar_script>
+  cat > "$home/fleet/agents/$agent.env.local" <<EOF
-# Record the full argument list to the capture file, then exit cleanly.
+MOSAIC_HEARTBEAT_RUN_DIR=$home/run
-printf '%s\0' "$@" > __SETSID_ARGS_FILE__
+MOSAIC_HEARTBEAT_INTERVAL=1
-exit 0
+EOF
-SETSID_SHIM
+  chmod 600 "$home/fleet/agents/$agent.env.local"
-# Patch the placeholder with the real capture-file path (avoids heredoc expansion issues).
+}
-sed -i "s|__SETSID_ARGS_FILE__|${SETSID_ARGS_FILE}|g" "$FAKE_BIN7/setsid"
-chmod +x "$FAKE_BIN7/setsid"
 
-SOCKET7="mosaic-agent-test7-$RANDOM-$$"
+wait_for_sidecar_status() {
-WORKDIR7=$(mktemp -d)
+  local file="$1"
-CLEANUP_DIRS+=("$WORKDIR7")
+  for _retry in $(seq 1 30); do
+    grep -qF 'status=ok' "$file" 2>/dev/null && return 0
+    sleep 0.1
+  done
+  fail "heartbeat sidecar did not resume after native marker became stale or absent"
+}
 
-PATH="$FAKE_BIN7:$PATH" \
+# A fresh Pi-native marker is authoritative: the shell sidecar may start but
-MOSAIC_TMUX_SOCKET="$SOCKET7" \
+# must not overwrite Pi's busy/ok/model heartbeat. It must resume only when
-MOSAIC_AGENT_WORKDIR="$WORKDIR7" \
+# the marker is stale or absent.
-MOSAIC_AGENT_RUNTIME="pi" \
+HOME_NATIVE_FRESH="$ROOT/native-fresh"
-MOSAIC_RUNTIME_BIN="$FAKE_RUNTIME_BIN7" \
+write_generated "$HOME_NATIVE_FRESH" "coder-native-fresh"
-MOSAIC_AGENT_COMMAND="mosaic yolo pi" \
+write_heartbeat_local "$HOME_NATIVE_FRESH" "coder-native-fresh"
-MOSAIC_HEARTBEAT_RUN_DIR="$HB_RUN_DIR7" \
+FRESH_HB="$HOME_NATIVE_FRESH/run/coder-native-fresh.hb"
-MOSAIC_HEARTBEAT_INTERVAL="$INTERVAL7" \
+printf 'ts=native\npid=1\nstatus=busy\nmodel=authoritative-model\n' > "$FRESH_HB"
-  "$START" "$AGENT7"
+touch "$FRESH_HB.native"
+MOSAIC_TEST_PANE_PID=$$ run_start "$HOME_NATIVE_FRESH" coder-native-fresh
+sleep 0.3
+fresh_content=$(cat "$FRESH_HB")
+[ "$fresh_content" = 'ts=native
+pid=1
+status=busy
+model=authoritative-model' ] || fail "fresh native heartbeat was overwritten"
 
-# Give the background setsid shim a moment to finish writing the capture file.
+HOME_NATIVE_STALE="$ROOT/native-stale"
-sleep 0.5
+write_generated "$HOME_NATIVE_STALE" "coder-native-stale"
+write_heartbeat_local "$HOME_NATIVE_STALE" "coder-native-stale"
+STALE_HB="$HOME_NATIVE_STALE/run/coder-native-stale.hb"
+printf 'ts=native\npid=1\nstatus=busy\nmodel=stale-model\n' > "$STALE_HB"
+touch -d '10 seconds ago' "$STALE_HB.native"
+MOSAIC_TEST_PANE_PID=$$ run_start "$HOME_NATIVE_STALE" coder-native-stale
+wait_for_sidecar_status "$STALE_HB"
 
-setsid_args=$(cat "$SETSID_ARGS_FILE" 2>/dev/null | tr '\0' '\n' || true)
+HOME_NATIVE_ABSENT="$ROOT/native-absent"
-rm -f "$SETSID_ARGS_FILE"
+write_generated "$HOME_NATIVE_ABSENT" "coder-native-absent"
-rm -rf "$WORKDIR7"
+write_heartbeat_local "$HOME_NATIVE_ABSENT" "coder-native-absent"
+ABSENT_HB="$HOME_NATIVE_ABSENT/run/coder-native-absent.hb"
+printf 'ts=native\npid=1\nstatus=busy\nmodel=absent-model\n' > "$ABSENT_HB"
+MOSAIC_TEST_PANE_PID=$$ run_start "$HOME_NATIVE_ABSENT" coder-native-absent
+wait_for_sidecar_status "$ABSENT_HB"
 
-echo "--- test 7: captured setsid args ---"
+# The interaction wrapper delegates to the shared strict parser before applying
-echo "$setsid_args"
+# its pinned policy, so malformed projection data wins over profile diagnostics.
-echo "--- end test 7 ---"
+: > "$TMUX_CALLS"
+HOME_INTERACTION_MALFORMED="$ROOT/interaction-malformed"
+write_interaction_generated "$HOME_INTERACTION_MALFORMED" "interaction-malformed"
+printf 'UNTRUSTED_BOOTSTRAP=value\n' >> "$HOME_INTERACTION_MALFORMED/fleet/agents/interaction-malformed.env.generated"
+if output=$(run_interaction "$HOME_INTERACTION_MALFORMED" interaction-malformed 2>&1); then
+  fail "interaction wrapper accepted malformed generated data"
+fi
+[ ! -s "$TMUX_CALLS" ] || fail "tmux ran before interaction strict-parser rejection"
+echo "$output" | grep -qF 'code=unknown-key' || fail "interaction did not use shared strict parser first"
 
-# The sidecar script (bash -c <script>) must reference the correct .hb path.
+# A syntactically valid but policy-incompatible projection reaches the pinned
-expected_hb="${HB_RUN_DIR7}/${AGENT7}.hb"
+# interaction policy check only after strict parsing and never starts tmux.
-echo "$setsid_args" | grep -qF "$expected_hb" || \
+: > "$TMUX_CALLS"
-  fail "test7: sidecar script does not reference correct .hb path ($expected_hb)"
+HOME_INTERACTION_POLICY="$ROOT/interaction-policy"
+write_interaction_generated "$HOME_INTERACTION_POLICY" "interaction-policy"
+perl -0pi -e 's/MOSAIC_AGENT_RUNTIME=pi/MOSAIC_AGENT_RUNTIME=codex/' \
+  "$HOME_INTERACTION_POLICY/fleet/agents/interaction-policy.env.generated"
+if output=$(run_interaction "$HOME_INTERACTION_POLICY" interaction-policy 2>&1); then
+  fail "interaction wrapper accepted a policy-incompatible projection"
+fi
+interaction_policy_args=$(tr '\0' '\n' < "$TMUX_CALLS")
+echo "$interaction_policy_args" | grep -qF 'new-session' && \
+  fail "interaction pinned-policy rejection created a tmux session"
+echo "$output" | grep -qF 'operator interaction service requires runtime pi' || \
+  fail "interaction pinned-policy check did not follow strict parsing"
 
-# The sidecar script must use the configured interval.
+# Exact stop derives the socket exclusively from the validated generated
-echo "$setsid_args" | grep -qF "$INTERVAL7" || \
+# projection and ignores an ambient socket supplied by the caller.
-  fail "test7: sidecar script does not reference configured interval ($INTERVAL7)"
+: > "$TMUX_CALLS"
+HOME_STOP="$ROOT/stop"
+write_generated "$HOME_STOP" "coder-stop"
+HOME="$HOME_STOP" PATH="$FAKE_BIN:$PATH" MOSAIC_TEST_TMUX_CALLS="$TMUX_CALLS" \
+  MOSAIC_TEST_HOME="$HOME_STOP" \
+  MOSAIC_TEST_FLEET_OWNER=123e4567-e89b-12d3-a456-426614174000 \
+  MOSAIC_HOME="$HOME_STOP" MOSAIC_TMUX_SOCKET=ambient-socket "$START" --stop coder-stop
+stop_args=$(tr '\0' '\n' < "$TMUX_CALLS")
+echo "$stop_args" | grep -qxF 'mosaic-test' || fail "exact stop did not use the validated generated socket"
+echo "$stop_args" | grep -qxF 'kill-session' || fail "exact stop did not request session termination"
+echo "$stop_args" | grep -qxF '=coder-stop' || fail "exact stop did not exact-match the generated agent name"
+if echo "$stop_args" | grep -qF 'ambient-socket'; then
+  fail "exact stop trusted an ambient socket"
+fi
 
-echo "ok - start-agent-session"
+echo 'ok - start-agent-session generated environment boundary'

packages/mosaic/src/commands/fleet-personas.spec.ts

@@ -1,13 +1,18 @@
-import { cp, mkdir, mkdtemp, rm, writeFile } from 'node:fs/promises';
+import { cp, mkdir, mkdtemp, rm, symlink, writeFile } from 'node:fs/promises';
 import { tmpdir } from 'node:os';
-import { dirname, join, resolve } from 'node:path';
+import { dirname, join, relative, resolve } from 'node:path';
 import { fileURLToPath } from 'node:url';
 import { afterEach, beforeEach, describe, expect, it } from 'vitest';
 import {
+  authorityForCanonicalClass,
+  canonicalizeRoleClass,
   extractClassesFromDir,
+  extractClassesFromDirSync,
   listPersonaClasses,
   personaStatus,
   resolvePersona,
+  resolvePersonaFrom,
+  resolvePersonaSync,
 } from './fleet-personas.js';
 import { loadProfiles, validateProfile, type FleetProfile } from './fleet-profiles.js';
 
@@ -54,13 +59,156 @@ afterEach(async () => {
   await rm(tmp, { recursive: true, force: true });
 });
 
+describe('FCM class canonicalization and authority', () => {
+  it.each([
+    ['implementer', 'code'],
+    ['reviewer', 'review'],
+    ['operator-interaction', 'interaction'],
+  ])('canonicalizes the approved alias %s to %s', (requested: string, canonical: string) => {
+    expect(canonicalizeRoleClass(requested)).toEqual({
+      requestedClass: requested,
+      canonicalClass: canonical,
+    });
+  });
+
+  it.each(['worker', 'analyst', 'canary', 'tess', 'ultron', 'constructor'])(
+    'does not infer an alias for %s',
+    (requested: string) => {
+      expect(canonicalizeRoleClass(requested)).toEqual({
+        requestedClass: requested,
+        canonicalClass: requested,
+      });
+    },
+  );
+
+  it('resolves inherited-property class names without granting protected authority', async () => {
+    await mkdir(overrideDir, { recursive: true });
+    await writeFile(
+      join(overrideDir, 'constructor.md'),
+      overridePersona('constructor', 'custom'),
+      'utf8',
+    );
+
+    const resolved = await resolvePersona('constructor', { rolesDir, overrideDir });
+    expect(resolved).toMatchObject({
+      requestedClass: 'constructor',
+      canonicalClass: 'constructor',
+      klass: 'constructor',
+      layer: 'override',
+    });
+    expect(authorityForCanonicalClass('constructor')).toMatchObject({
+      mayMerge: false,
+      mayIssueValidationCertificate: false,
+      mayOrchestrate: false,
+    });
+  });
+
+  it('canonicalizes before override lookup and lets the canonical override win', async () => {
+    await mkdir(overrideDir, { recursive: true });
+    await writeFile(
+      join(overrideDir, 'implementer.md'),
+      overridePersona('implementer', 'legacy'),
+      'utf8',
+    );
+    await writeFile(
+      join(overrideDir, 'code.md'),
+      overridePersona('code', 'engineering', 'CANONICAL-OVERRIDE'),
+      'utf8',
+    );
+
+    const resolved = await resolvePersona('implementer', { rolesDir, overrideDir });
+    expect(resolved).toMatchObject({
+      requestedClass: 'implementer',
+      canonicalClass: 'code',
+      klass: 'code',
+      layer: 'override',
+    });
+    expect(resolved?.content).toContain('CANONICAL-OVERRIDE');
+    expect(resolved?.content).not.toContain('legacy');
+  });
+
+  it('keeps sync and async resolution equivalent for aliases and canonical overrides', async () => {
+    await mkdir(overrideDir, { recursive: true });
+    await writeFile(
+      join(overrideDir, 'code.md'),
+      overridePersona('code', 'engineering', 'CANONICAL-OVERRIDE'),
+      'utf8',
+    );
+
+    const asyncResolution = await resolvePersona('implementer', { rolesDir, overrideDir });
+    const syncResolution = resolvePersonaSync('implementer', { rolesDir, overrideDir });
+    expect(syncResolution).toEqual(asyncResolution);
+  });
+
+  it('derives immutable protected authority only from the canonical class', () => {
+    expect(authorityForCanonicalClass('merge-gate')).toMatchObject({ mayMerge: true });
+    for (const klass of [
+      'validator',
+      'orchestrator',
+      'team-leader',
+      'interaction',
+      'code',
+      'custom-role',
+    ]) {
+      expect(authorityForCanonicalClass(klass).mayMerge).toBe(false);
+    }
+    expect(authorityForCanonicalClass('validator')).toMatchObject({
+      mayIssueValidationCertificate: true,
+      mayMerge: false,
+    });
+    expect(authorityForCanonicalClass('orchestrator')).toMatchObject({
+      mayOrchestrate: true,
+      mayIssueLeases: true,
+      mayMerge: false,
+    });
+    expect(authorityForCanonicalClass('team-leader')).toMatchObject({
+      leasedCapacityOnly: true,
+      mayMutateRoster: false,
+      mayAccessCredentials: false,
+      mayMerge: false,
+    });
+    expect(authorityForCanonicalClass('interaction')).toMatchObject({
+      requestStatusOnly: true,
+      mayOrchestrate: false,
+      mayMerge: false,
+    });
+    expect(Object.isFrozen(authorityForCanonicalClass('merge-gate'))).toBe(true);
+  });
+});
+
+describe('required FCM role library', () => {
+  it.each([
+    'code',
+    'review',
+    'validator',
+    'orchestrator',
+    'team-leader',
+    'enhancer',
+    'interaction',
+    'merge-gate',
+  ])('resolves %s through the real framework role library', async (klass: string) => {
+    const resolved = await resolvePersona(klass, {
+      rolesDir: realRolesDir,
+      overrideDir: join(tmp, 'none'),
+    });
+    expect(resolved).not.toBeNull();
+    expect(resolved?.canonicalClass).toBe(klass);
+    expect(resolved?.content.trim()).not.toBe('');
+  });
+});
+
 describe('extractClassesFromDir (shared extraction)', () => {
-  it('records class + domain from inline markers and degrades on missing dir', async () => {
+  it('records class + domain and distinguishes scanned from missing directories', async () => {
     const base = await extractClassesFromDir(rolesDir);
+    expect(base.scanState).toBe('scanned');
     expect(base.classes.has('ceo')).toBe(true);
     expect(base.byClass.get('ceo')?.domain).toBe('executive');
-    const missing = await extractClassesFromDir(join(tmp, 'nope'));
+
+    const missingDir = join(tmp, 'nope');
+    const missing = await extractClassesFromDir(missingDir);
+    expect(missing.scanState).toBe('missing');
     expect(missing.classes.size).toBe(0);
+    expect(extractClassesFromDirSync(missingDir).scanState).toBe('missing');
   });
 });
 
@@ -81,6 +229,287 @@ describe('resolvePersona — override wins', () => {
     expect(resolved?.content).toContain('BASELINE');
   });
 
+  it('does not let a LIBRARY-only row shadow a readable baseline persona', async () => {
+    await mkdir(overrideDir, { recursive: true });
+    await writeFile(
+      join(overrideDir, 'LIBRARY.md'),
+      '| Persona | Purpose |\n| --- | --- |\n| code | Index only |\n',
+      'utf8',
+    );
+
+    const resolved = await resolvePersona('code', { rolesDir, overrideDir });
+    expect(resolved?.layer).toBe('baseline');
+    expect(resolved?.content).toContain('BASELINE');
+    expect((await listPersonaClasses({ rolesDir, overrideDir })).has('code')).toBe(true);
+    expect(
+      (await personaStatus({ rolesDir, overrideDir })).find(({ klass }) => klass === 'code')
+        ?.status,
+    ).toBe('baseline');
+  });
+
+  it('does not let an incidental later class marker shadow a readable baseline persona', async () => {
+    await mkdir(overrideDir, { recursive: true });
+    await writeFile(
+      join(overrideDir, 'mascot.md'),
+      '# mascot\n\n(`class: mascot`)\n\nSee also (`class: code`).\n',
+      'utf8',
+    );
+
+    const resolved = await resolvePersona('code', { rolesDir, overrideDir });
+    expect(resolved?.layer).toBe('baseline');
+    expect(resolved?.content).toContain('BASELINE');
+    expect((await listPersonaClasses({ rolesDir, overrideDir })).has('code')).toBe(true);
+    expect((await listPersonaClasses({ rolesDir, overrideDir })).has('mascot')).toBe(true);
+    expect(
+      (await personaStatus({ rolesDir, overrideDir })).find(({ klass }) => klass === 'code')
+        ?.status,
+    ).toBe('baseline');
+  });
+
+  it('does not advertise an incidental-only class through listing or status APIs', async () => {
+    await mkdir(overrideDir, { recursive: true });
+    await writeFile(
+      join(overrideDir, 'mascot.md'),
+      '# mascot\n\n(`class: mascot`)\n\nSee also (`class: phantom`).\n',
+      'utf8',
+    );
+
+    expect((await listPersonaClasses({ rolesDir, overrideDir })).has('phantom')).toBe(false);
+    expect(
+      (await personaStatus({ rolesDir, overrideDir })).some(({ klass }) => klass === 'phantom'),
+    ).toBe(false);
+  });
+
+  it('rejects a canonical filename whose explicit marker names another class', async () => {
+    await mkdir(overrideDir, { recursive: true });
+    await writeFile(join(overrideDir, 'merge-gate.md'), overridePersona('mascot', 'fun'), 'utf8');
+    await writeFile(
+      join(rolesDir, 'merge-gate.md'),
+      baselinePersona('merge-gate', 'governance'),
+      'utf8',
+    );
+
+    expect(await resolvePersona('merge-gate', { rolesDir, overrideDir })).toBeNull();
+    expect(resolvePersonaSync('merge-gate', { rolesDir, overrideDir })).toBeNull();
+    expect((await listPersonaClasses({ rolesDir, overrideDir })).has('merge-gate')).toBe(false);
+    expect(
+      (await personaStatus({ rolesDir, overrideDir })).some(({ klass }) => klass === 'merge-gate'),
+    ).toBe(false);
+  });
+
+  it('fails closed if a marker-defined override becomes unreadable after extraction', async () => {
+    await mkdir(overrideDir, { recursive: true });
+    const overrideFile = join(overrideDir, 'engineering.md');
+    await writeFile(overrideFile, overridePersona('code', 'engineering'), 'utf8');
+    const [base, over] = await Promise.all([
+      extractClassesFromDir(rolesDir),
+      extractClassesFromDir(overrideDir),
+    ]);
+    await rm(overrideFile);
+    await mkdir(overrideFile);
+
+    expect(await resolvePersonaFrom('code', { rolesDir, overrideDir, base, over })).toBeNull();
+  });
+
+  it('fails closed if a marker-defined override changes identity after extraction', async () => {
+    await mkdir(overrideDir, { recursive: true });
+    const overrideFile = join(overrideDir, 'engineering.md');
+    await writeFile(overrideFile, overridePersona('code', 'engineering'), 'utf8');
+    const [base, over] = await Promise.all([
+      extractClassesFromDir(rolesDir),
+      extractClassesFromDir(overrideDir),
+    ]);
+    await writeFile(overrideFile, overridePersona('mascot', 'fun'), 'utf8');
+
+    expect(await resolvePersonaFrom('code', { rolesDir, overrideDir, base, over })).toBeNull();
+
+    const classes = await listPersonaClasses({ rolesDir, overrideDir });
+    expect(classes.has('code')).toBe(true);
+    expect(classes.has('mascot')).toBe(true);
+    const status = new Map(
+      (await personaStatus({ rolesDir, overrideDir })).map((entry) => [entry.klass, entry]),
+    );
+    expect(status.get('code')?.status).toBe('baseline');
+    expect(status.get('mascot')?.status).toBe('custom');
+  });
+
+  it('fails closed if a markerless cached override gains a conflicting marker', async () => {
+    await mkdir(overrideDir, { recursive: true });
+    const overrideFile = join(overrideDir, 'merge-gate.md');
+    await writeFile(overrideFile, '# markerless merge gate\n', 'utf8');
+    await writeFile(
+      join(rolesDir, 'merge-gate.md'),
+      baselinePersona('merge-gate', 'governance'),
+      'utf8',
+    );
+    const [base, over] = await Promise.all([
+      extractClassesFromDir(rolesDir),
+      extractClassesFromDir(overrideDir),
+    ]);
+    await writeFile(overrideFile, overridePersona('mascot', 'fun'), 'utf8');
+
+    expect(
+      await resolvePersonaFrom('merge-gate', { rolesDir, overrideDir, base, over }),
+    ).toBeNull();
+  });
+
+  it('fails closed asynchronously when the override directory cannot be scanned', async () => {
+    await writeFile(overrideDir, 'not a directory', 'utf8');
+    expect(await resolvePersona('code', { rolesDir, overrideDir })).toBeNull();
+  });
+
+  it('fails closed synchronously when the override directory cannot be scanned', async () => {
+    await writeFile(overrideDir, 'not a directory', 'utf8');
+    expect(resolvePersonaSync('code', { rolesDir, overrideDir })).toBeNull();
+  });
+
+  it('fails closed asynchronously and synchronously for a dangling override-directory symlink', async () => {
+    await symlink(join(tmp, 'missing-override-target'), overrideDir, 'dir');
+
+    expect(await resolvePersona('code', { rolesDir, overrideDir })).toBeNull();
+    expect(resolvePersonaSync('code', { rolesDir, overrideDir })).toBeNull();
+  });
+
+  it('fails closed asynchronously and synchronously when an override ancestor is a dangling symlink', async () => {
+    const danglingAncestor = join(tmp, 'dangling-ancestor');
+    await symlink(join(tmp, 'missing-ancestor-target'), danglingAncestor, 'dir');
+    overrideDir = join(danglingAncestor, 'nested', 'roles.local');
+
+    expect(await resolvePersona('code', { rolesDir, overrideDir })).toBeNull();
+    expect(resolvePersonaSync('code', { rolesDir, overrideDir })).toBeNull();
+    expect(await listPersonaClasses({ rolesDir, overrideDir })).toEqual(new Set());
+    expect(await personaStatus({ rolesDir, overrideDir })).toEqual([]);
+  });
+
+  it('fails closed when dot-dot traversal crosses a dangling override ancestor', async () => {
+    const danglingAncestor = join(tmp, 'dangling-dotdot-ancestor');
+    await symlink(join(tmp, 'missing-dotdot-target'), danglingAncestor, 'dir');
+    overrideDir = `${danglingAncestor}/../roles.local`;
+
+    expect(await resolvePersona('code', { rolesDir, overrideDir })).toBeNull();
+    expect(resolvePersonaSync('code', { rolesDir, overrideDir })).toBeNull();
+    expect(await listPersonaClasses({ rolesDir, overrideDir })).toEqual(new Set());
+    expect(await personaStatus({ rolesDir, overrideDir })).toEqual([]);
+  });
+
+  it('fails closed when relative dot-dot traversal crosses a dangling override ancestor', async () => {
+    const danglingAncestor = join(tmp, 'relative-dangling-ancestor');
+    await symlink(join(tmp, 'missing-relative-target'), danglingAncestor, 'dir');
+    overrideDir = `${relative(process.cwd(), danglingAncestor)}/../roles.local`;
+    expect(overrideDir.startsWith('/')).toBe(false);
+
+    expect(await resolvePersona('code', { rolesDir, overrideDir })).toBeNull();
+    expect(resolvePersonaSync('code', { rolesDir, overrideDir })).toBeNull();
+    expect(await listPersonaClasses({ rolesDir, overrideDir })).toEqual(new Set());
+    expect(await personaStatus({ rolesDir, overrideDir })).toEqual([]);
+  });
+
+  it('revalidates a cached missing override before baseline fallback', async () => {
+    const cachedOverrideDir = join(tmp, 'mutable-ancestor', 'roles.local');
+    const [base, over] = await Promise.all([
+      extractClassesFromDir(rolesDir),
+      extractClassesFromDir(cachedOverrideDir),
+    ]);
+    expect(over.scanState).toBe('missing');
+    await symlink(join(tmp, 'missing-mutable-target'), join(tmp, 'mutable-ancestor'), 'dir');
+
+    expect(
+      await resolvePersonaFrom('code', {
+        rolesDir,
+        overrideDir: cachedOverrideDir,
+        base,
+        over,
+      }),
+    ).toBeNull();
+  });
+
+  it('revalidates a cached scanned override before baseline fallback', async () => {
+    await mkdir(overrideDir, { recursive: true });
+    const [base, over] = await Promise.all([
+      extractClassesFromDir(rolesDir),
+      extractClassesFromDir(overrideDir),
+    ]);
+    expect(over.scanState).toBe('scanned');
+    expect(over.classes.size).toBe(0);
+
+    await writeFile(join(overrideDir, 'engineering.md'), overridePersona('code', 'engineering'));
+
+    const resolved = await resolvePersonaFrom('code', {
+      rolesDir,
+      overrideDir,
+      base,
+      over,
+    });
+    expect(resolved?.layer).toBe('override');
+    expect(resolved?.file).toBe(join(overrideDir, 'engineering.md'));
+  });
+
+  it('falls back to baseline asynchronously and synchronously when override directory is missing', async () => {
+    const asyncResolution = await resolvePersona('code', { rolesDir, overrideDir });
+    const syncResolution = resolvePersonaSync('code', { rolesDir, overrideDir });
+    expect(asyncResolution?.layer).toBe('baseline');
+    expect(syncResolution?.layer).toBe('baseline');
+  });
+
+  it('fails closed asynchronously when the canonical override exists but is unreadable', async () => {
+    await mkdir(overrideDir, { recursive: true });
+    await mkdir(join(overrideDir, 'code.md'));
+
+    expect(await resolvePersona('code', { rolesDir, overrideDir })).toBeNull();
+  });
+
+  it('does not advertise a shadowed baseline whose canonical override is unreadable', async () => {
+    await mkdir(overrideDir, { recursive: true });
+    await mkdir(join(overrideDir, 'code.md'));
+
+    expect((await listPersonaClasses({ rolesDir, overrideDir })).has('code')).toBe(false);
+    expect(
+      (await personaStatus({ rolesDir, overrideDir })).some(({ klass }) => klass === 'code'),
+    ).toBe(false);
+  });
+
+  it('does not advertise baseline personas when the override directory is unscannable', async () => {
+    await writeFile(overrideDir, 'not a directory', 'utf8');
+
+    expect(await listPersonaClasses({ rolesDir, overrideDir })).toEqual(new Set());
+    expect(await personaStatus({ rolesDir, overrideDir })).toEqual([]);
+  });
+
+  it('does not advertise baseline personas through a dangling override-directory symlink', async () => {
+    await symlink(join(tmp, 'missing-override-target'), overrideDir, 'dir');
+
+    expect(await listPersonaClasses({ rolesDir, overrideDir })).toEqual(new Set());
+    expect(await personaStatus({ rolesDir, overrideDir })).toEqual([]);
+  });
+
+  it('preserves baseline listings when the override directory is missing', async () => {
+    expect((await listPersonaClasses({ rolesDir, overrideDir })).has('code')).toBe(true);
+    expect(
+      (await personaStatus({ rolesDir, overrideDir })).find(({ klass }) => klass === 'code')
+        ?.status,
+    ).toBe('baseline');
+  });
+
+  it('does not advertise an unreadable custom override as a valid persona class or status', async () => {
+    await mkdir(overrideDir, { recursive: true });
+    await mkdir(join(overrideDir, 'ghost.md'));
+
+    const extracted = await extractClassesFromDir(overrideDir);
+    expect(extracted.fileStems.has('ghost')).toBe(true);
+    expect(extracted.classes.has('ghost')).toBe(false);
+    expect((await listPersonaClasses({ rolesDir, overrideDir })).has('ghost')).toBe(false);
+    expect(
+      (await personaStatus({ rolesDir, overrideDir })).some(({ klass }) => klass === 'ghost'),
+    ).toBe(false);
+  });
+
+  it('fails closed synchronously when the canonical override exists but is unreadable', async () => {
+    await mkdir(overrideDir, { recursive: true });
+    await mkdir(join(overrideDir, 'code.md'));
+
+    expect(resolvePersonaSync('code', { rolesDir, overrideDir })).toBeNull();
+  });
+
   it('returns null for an unknown class', async () => {
     expect(await resolvePersona('does-not-exist', { rolesDir, overrideDir })).toBeNull();
   });

packages/mosaic/src/commands/fleet-personas.ts

@@ -25,10 +25,10 @@
  * can reference a customized or user-added persona.
  */
 
-import { readFileSync, readdirSync } from 'node:fs';
+import { lstatSync, readFileSync, readdirSync, statSync } from 'node:fs';
-import { readFile, readdir } from 'node:fs/promises';
+import { lstat, readFile, readdir, stat } from 'node:fs/promises';
 import { homedir } from 'node:os';
-import { basename, join } from 'node:path';
+import { basename, isAbsolute, join, sep } from 'node:path';
 import type { Command } from 'commander';
 
 function defaultMosaicHome(): string {
@@ -53,52 +53,136 @@ export function defaultOverrideDir(mosaicHome = defaultMosaicHome()): string {
 const CLASS_MARKER = /`?class:\s*\n?\s*([a-z][a-z0-9-]*)`?/g;
 /** Optional `domain: Y` marker that travels alongside the class in the prose. */
 const DOMAIN_MARKER = /`?domain:\s*\n?\s*([a-z][a-z0-9-]*)`?/;
-/** LIBRARY.md persona rows: the first table cell is the persona name. */
-const LIBRARY_ROW = /^\|\s*([a-z][a-z0-9-]*)\s*\|/gm;
 
 /** Where a resolved persona's definition came from. */
 export type PersonaLayer = 'baseline' | 'override';
 
+export const ROLE_CLASS_ALIASES = Object.freeze({
+  implementer: 'code',
+  reviewer: 'review',
+  'operator-interaction': 'interaction',
+} as const);
+
+export interface CanonicalRoleClass {
+  readonly requestedClass: string;
+  readonly canonicalClass: string;
+}
+
+/** Canonicalize only the three explicitly approved compatibility aliases. */
+export function canonicalizeRoleClass(requestedClass: string): CanonicalRoleClass {
+  const requested = requestedClass.trim();
+  const canonical = Object.hasOwn(ROLE_CLASS_ALIASES, requested)
+    ? ROLE_CLASS_ALIASES[requested as keyof typeof ROLE_CLASS_ALIASES]
+    : requested;
+  return Object.freeze({ requestedClass: requested, canonicalClass: canonical });
+}
+
+export interface RoleAuthority {
+  readonly mayMerge: boolean;
+  readonly mayIssueValidationCertificate: boolean;
+  readonly mayOrchestrate: boolean;
+  readonly mayManageTopology: boolean;
+  readonly mayIssueLeases: boolean;
+  readonly leasedCapacityOnly: boolean;
+  readonly requestStatusOnly: boolean;
+  readonly mayMutateRoster: boolean;
+  readonly mayMutateConfiguration: boolean;
+  readonly mayAccessCredentials: boolean;
+}
+
+const NO_PROTECTED_AUTHORITY: RoleAuthority = Object.freeze({
+  mayMerge: false,
+  mayIssueValidationCertificate: false,
+  mayOrchestrate: false,
+  mayManageTopology: false,
+  mayIssueLeases: false,
+  leasedCapacityOnly: false,
+  requestStatusOnly: false,
+  mayMutateRoster: false,
+  mayMutateConfiguration: false,
+  mayAccessCredentials: false,
+});
+
+/** Immutable authority contracts keyed only by canonical class identity. */
+export const ROLE_AUTHORITY_BY_CANONICAL_CLASS: Readonly<Record<string, RoleAuthority>> =
+  Object.freeze({
+    'merge-gate': Object.freeze({ ...NO_PROTECTED_AUTHORITY, mayMerge: true }),
+    validator: Object.freeze({
+      ...NO_PROTECTED_AUTHORITY,
+      mayIssueValidationCertificate: true,
+    }),
+    orchestrator: Object.freeze({
+      ...NO_PROTECTED_AUTHORITY,
+      mayOrchestrate: true,
+      mayManageTopology: true,
+      mayIssueLeases: true,
+    }),
+    'team-leader': Object.freeze({ ...NO_PROTECTED_AUTHORITY, leasedCapacityOnly: true }),
+    interaction: Object.freeze({ ...NO_PROTECTED_AUTHORITY, requestStatusOnly: true }),
+  });
+
+/** Return protected authority for an already-canonical class; custom classes get none. */
+export function authorityForCanonicalClass(canonicalClass: string): RoleAuthority {
+  return Object.hasOwn(ROLE_AUTHORITY_BY_CANONICAL_CLASS, canonicalClass)
+    ? ROLE_AUTHORITY_BY_CANONICAL_CLASS[canonicalClass]!
+    : NO_PROTECTED_AUTHORITY;
+}
+
 /** One discovered persona file (a single role contract on disk). */
 export interface PersonaFile {
   klass: string;
   /** The markdown file the class was found in. */
   file: string;
+  /** True when the first class marker, rather than filename, defined this mapping. */
+  markerDefined?: boolean;
   domain?: string;
 }
 
+export type DirScanState = 'scanned' | 'missing' | 'error';
+
 /** The set of persona classes a directory of role contracts defines. */
 export interface DirClasses {
-  /** Every class name the dir contributes (markers + filenames + LIBRARY rows). */
+  /** Whether the directory was scanned, absent, or present-but-unscannable. */
+  scanState: DirScanState;
+  /** Every readable class name the directory contributes by filename or first marker. */
   classes: Set<string>;
+  /** Filename stems present on disk, retained even when a markdown entry is unreadable. */
+  fileStems: Set<string>;
   /** For classes whose file carries a marker, the file + domain that defined it. */
   byClass: Map<string, PersonaFile>;
 }
 
 /**
- * Scan one directory of role contracts and extract the persona classes it
+ * Scan one directory of role contracts and extract readable persona identities.
- * defines. THIS is the shared extraction both fleet-personas and fleet-profiles
+ * Valid identities come only from a successfully read non-LIBRARY filename and
- * rely on. Sources, unioned (each needed — see module doc):
+ * that file's first `class:` marker. LIBRARY rows and later prose mentions are
- *   1. inline `class: X` markers in roles/*.md (primary; may wrap a newline),
+ * index/reference data, not independently readable role contracts.
- *   2. persona-name cells from LIBRARY.md index tables,
- *   3. the role filename stem (covers marker-less alias docs like planner).
  *
- * Missing dir / unreadable files degrade gracefully to whatever was found.
+ * Missing directories are distinguished from present-but-unscannable paths.
- * `byClass` records the defining file+domain for marker-bearing classes so the
+ * `byClass` records the first marker-defined file+domain so the resolver can map
- * resolver can map a class back to its file; filename-only and LIBRARY-only
+ * a class back to its contract; marker-less readable files map by filename.
- * classes still appear in `classes` for membership checks.
  */
 export async function extractClassesFromDir(dir: string): Promise<DirClasses> {
-  const acc: DirClasses = { classes: new Set<string>(), byClass: new Map<string, PersonaFile>() };
+  const acc: DirClasses = {
+    scanState: 'scanned',
+    classes: new Set<string>(),
+    fileStems: new Set<string>(),
+    byClass: new Map<string, PersonaFile>(),
+  };
   let entries: string[];
   try {
     entries = await readdir(dir);
-  } catch {
+  } catch (error) {
+    acc.scanState = await classifyScanFailure(dir, error);
     return acc;
   }
 
   for (const entry of entries) {
     if (!entry.endsWith('.md')) continue;
+    // Preserve entry presence separately from valid readable classes. Resolvers
+    // use it to fail closed on an explicit unreadable canonical override without
+    // advertising that override through class listing/status APIs.
+    if (entry !== 'LIBRARY.md') acc.fileStems.add(basename(entry, '.md'));
     let text: string;
     try {
       text = await readFile(join(dir, entry), 'utf8');
@@ -117,16 +201,25 @@ export async function extractClassesFromDir(dir: string): Promise<DirClasses> {
  * cannot await. Missing dir / unreadable files degrade gracefully.
  */
 export function extractClassesFromDirSync(dir: string): DirClasses {
-  const acc: DirClasses = { classes: new Set<string>(), byClass: new Map<string, PersonaFile>() };
+  const acc: DirClasses = {
+    scanState: 'scanned',
+    classes: new Set<string>(),
+    fileStems: new Set<string>(),
+    byClass: new Map<string, PersonaFile>(),
+  };
   let entries: string[];
   try {
     entries = readdirSync(dir);
-  } catch {
+  } catch (error) {
+    acc.scanState = classifyScanFailureSync(dir, error);
     return acc;
   }
 
   for (const entry of entries) {
     if (!entry.endsWith('.md')) continue;
+    // Keep sync extraction equivalent to the async scanner, including unreadable
+    // filename presence kept separate from valid readable classes.
+    if (entry !== 'LIBRARY.md') acc.fileStems.add(basename(entry, '.md'));
     let text: string;
     try {
       text = readFileSync(join(dir, entry), 'utf8');
@@ -138,6 +231,74 @@ export function extractClassesFromDirSync(dir: string): DirClasses {
   return acc;
 }
 
+async function classifyScanFailure(dir: string, error: unknown): Promise<DirScanState> {
+  if (!isMissingPathError(error)) return 'error';
+  return (await hasBrokenSymlinkInPath(dir)) ? 'error' : 'missing';
+}
+
+function classifyScanFailureSync(dir: string, error: unknown): DirScanState {
+  if (!isMissingPathError(error)) return 'error';
+  return hasBrokenSymlinkInPathSync(dir) ? 'error' : 'missing';
+}
+
+function traversalPrefixes(path: string): string[] {
+  const absolute = isAbsolute(path) ? path : `${process.cwd()}${sep}${path}`;
+  const parts = absolute.split(sep);
+  const prefixes: string[] = [];
+  let current: string = sep;
+  for (const part of parts) {
+    if (!part) continue;
+    current = current === sep ? `${sep}${part}` : `${current}${sep}${part}`;
+    prefixes.push(current);
+  }
+  return prefixes;
+}
+
+async function hasBrokenSymlinkInPath(path: string): Promise<boolean> {
+  for (const current of traversalPrefixes(path)) {
+    try {
+      const entry = await lstat(current);
+      if (entry.isSymbolicLink()) {
+        try {
+          await stat(current);
+        } catch {
+          return true;
+        }
+      }
+    } catch (error) {
+      if (!isMissingPathError(error)) return true;
+    }
+  }
+  return false;
+}
+
+function hasBrokenSymlinkInPathSync(path: string): boolean {
+  for (const current of traversalPrefixes(path)) {
+    try {
+      const entry = lstatSync(current);
+      if (entry.isSymbolicLink()) {
+        try {
+          statSync(current);
+        } catch {
+          return true;
+        }
+      }
+    } catch (error) {
+      if (!isMissingPathError(error)) return true;
+    }
+  }
+  return false;
+}
+
+function isMissingPathError(error: unknown): boolean {
+  return (
+    typeof error === 'object' &&
+    error !== null &&
+    'code' in error &&
+    (error as { code?: unknown }).code === 'ENOENT'
+  );
+}
+
 /**
  * Apply the class-extraction rules for ONE role file's text into `acc`. Pure
  * over already-read content, so the async and sync directory scanners share a
@@ -146,33 +307,26 @@ export function extractClassesFromDirSync(dir: string): DirClasses {
  */
 function accumulateEntry(acc: DirClasses, dir: string, entry: string, text: string): void {
   const { classes, byClass } = acc;
-  if (entry === 'LIBRARY.md') {
+  if (entry === 'LIBRARY.md') return;
-    for (const m of text.matchAll(LIBRARY_ROW)) {
+
-      const name = m[1];
+  // An explicit first marker owns identity. Filename identity is a fallback only
-      if (name && name !== 'persona') classes.add(name);
+  // for markerless compatibility contracts such as planner.md.
-    }
-    return;
-  }
-  // The filename stem is itself a valid class (covers marker-less alias docs).
   const stem = basename(entry, '.md');
-  classes.add(stem);
   const domainMatch = DOMAIN_MARKER.exec(text);
   const domain = domainMatch?.[1];
-  let markedClassForFile: string | undefined;
+  const firstMarker = text.matchAll(CLASS_MARKER).next().value as RegExpExecArray | undefined;
-  for (const m of text.matchAll(CLASS_MARKER)) {
+  const markedClassForFile = firstMarker?.[1];
-    const klass = m[1];
+  if (markedClassForFile) {
-    if (!klass) continue;
+    classes.add(markedClassForFile);
-    classes.add(klass);
+    byClass.set(markedClassForFile, {
-    // Record the FIRST marker as the file's defining class (the prose names
+      klass: markedClassForFile,
-    // the persona's own class up top; later mentions reference siblings).
+      file: join(dir, entry),
-    if (!markedClassForFile) {
+      markerDefined: true,
-      markedClassForFile = klass;
+      ...(domain ? { domain } : {}),
-      byClass.set(klass, { klass, file: join(dir, entry), ...(domain ? { domain } : {}) });
+    });
-    }
+  } else {
-  }
+    classes.add(stem);
-  // A marker-less file still maps its stem to itself (no domain known).
+    if (!byClass.has(stem)) byClass.set(stem, { klass: stem, file: join(dir, entry) });
-  if (!markedClassForFile && !byClass.has(stem)) {
-    byClass.set(stem, { klass: stem, file: join(dir, entry) });
   }
 }
 
@@ -193,24 +347,19 @@ function resolveDirs(opts: PersonaDirs): { rolesDir: string; overrideDir: string
 }
 
 /**
- * UNION of baseline classes and override classes. Overrides may ADD entirely new
+ * Every class with an actually readable winning contract. Discovery applies the
- * classes not present in the baseline, so callers (e.g. profile roster
+ * same override shadow/fail-closed semantics as resolution, so callers never
- * validation) treat a user-added persona as a real class.
+ * advertise a class that cannot be used.
  */
 export async function listPersonaClasses(opts: PersonaDirs = {}): Promise<Set<string>> {
-  const { rolesDir, overrideDir } = resolveDirs(opts);
+  const { personas } = await collectUsablePersonas(opts);
-  const [base, over] = await Promise.all([
+  return new Set(personas.keys());
-    extractClassesFromDir(rolesDir),
-    extractClassesFromDir(overrideDir),
-  ]);
-  const union = new Set<string>(base.classes);
-  for (const c of over.classes) union.add(c);
-  return union;
 }
 
 export type PersonaStatus = 'baseline' | 'overridden' | 'custom';
 
-export interface PersonaResolution {
+export interface PersonaResolution extends CanonicalRoleClass {
+  /** Compatibility name for the canonical class. */
   klass: string;
   layer: PersonaLayer;
   /** The file the resolved persona was read from (override wins). */
@@ -219,6 +368,118 @@ export interface PersonaResolution {
   domain?: string;
 }
 
+async function readPersonaFromLayer(
+  requestedClass: string,
+  canonicalClass: string,
+  dir: string,
+  extracted: DirClasses,
+  layer: PersonaLayer,
+): Promise<PersonaResolution | null> {
+  const pf = extracted.byClass.get(canonicalClass);
+  if (!pf) {
+    if (!extracted.classes.has(canonicalClass)) return null;
+    const byName = join(dir, `${canonicalClass}.md`);
+    try {
+      const content = await readFile(byName, 'utf8');
+      const currentMarker = content.matchAll(CLASS_MARKER).next().value as
+        | RegExpExecArray
+        | undefined;
+      if (currentMarker && currentMarker[1] !== canonicalClass) return null;
+      const dm = DOMAIN_MARKER.exec(content);
+      return {
+        requestedClass,
+        canonicalClass,
+        klass: canonicalClass,
+        layer,
+        file: byName,
+        content,
+        ...(dm?.[1] ? { domain: dm[1] } : {}),
+      };
+    } catch {
+      return null;
+    }
+  }
+  try {
+    const content = await readFile(pf.file, 'utf8');
+    const currentMarker = content.matchAll(CLASS_MARKER).next().value as
+      | RegExpExecArray
+      | undefined;
+    if (currentMarker && currentMarker[1] !== canonicalClass) return null;
+    const dm = DOMAIN_MARKER.exec(content);
+    return {
+      requestedClass,
+      canonicalClass,
+      klass: canonicalClass,
+      layer,
+      file: pf.file,
+      content,
+      ...(dm?.[1] ? { domain: dm[1] } : {}),
+    };
+  } catch {
+    return null;
+  }
+}
+
+function overrideShadowsBaseline(over: DirClasses, canonicalClass: string): boolean {
+  return (
+    over.scanState === 'error' ||
+    over.fileStems.has(canonicalClass) ||
+    over.byClass.has(canonicalClass)
+  );
+}
+
+function readPersonaFromLayerSync(
+  requestedClass: string,
+  canonicalClass: string,
+  dir: string,
+  extracted: DirClasses,
+  layer: PersonaLayer,
+): PersonaResolution | null {
+  const pf = extracted.byClass.get(canonicalClass);
+  if (!pf) {
+    if (!extracted.classes.has(canonicalClass)) return null;
+    const byName = join(dir, `${canonicalClass}.md`);
+    try {
+      const content = readFileSync(byName, 'utf8');
+      const currentMarker = content.matchAll(CLASS_MARKER).next().value as
+        | RegExpExecArray
+        | undefined;
+      if (currentMarker && currentMarker[1] !== canonicalClass) return null;
+      const dm = DOMAIN_MARKER.exec(content);
+      return {
+        requestedClass,
+        canonicalClass,
+        klass: canonicalClass,
+        layer,
+        file: byName,
+        content,
+        ...(dm?.[1] ? { domain: dm[1] } : {}),
+      };
+    } catch {
+      return null;
+    }
+  }
+  try {
+    const content = readFileSync(pf.file, 'utf8');
+    const currentMarker = content.matchAll(CLASS_MARKER).next().value as
+      | RegExpExecArray
+      | undefined;
+    if (currentMarker && currentMarker[1] !== canonicalClass) return null;
+    const dm = DOMAIN_MARKER.exec(content);
+    return {
+      requestedClass,
+      canonicalClass,
+      klass: canonicalClass,
+      layer,
+      file: pf.file,
+      content,
+      ...(dm?.[1] ? { domain: dm[1] } : {}),
+    };
+  } catch {
+    return null;
+  }
+}
+
 /**
  * Resolve a persona class to its winning definition: the override file if
  * roles.local/ defines that class, else the baseline. Match by inline `class:`
@@ -245,42 +506,32 @@ export async function resolvePersona(
  * is identical to {@link resolvePersona}: override layer wins, then baseline.
  */
 export async function resolvePersonaFrom(
-  klass: string,
+  requestedClass: string,
   layers: { rolesDir: string; overrideDir: string; base: DirClasses; over: DirClasses },
 ): Promise<PersonaResolution | null> {
+  const { requestedClass: requested, canonicalClass: klass } =
+    canonicalizeRoleClass(requestedClass);
   const { rolesDir, overrideDir, base, over } = layers;
 
-  const fromLayer = async (
+  const override = await readPersonaFromLayer(requested, klass, overrideDir, over, 'override');
-    dir: string,
+  if (override) return override;
-    extracted: DirClasses,
+  // An observed explicit override that cannot resolve/read shadows the baseline.
-    layer: PersonaLayer,
+  if (overrideShadowsBaseline(over, klass)) return null;
-  ): Promise<PersonaResolution | null> => {
-    // Prefer the marker-defined file; fall back to the filename stem.
-    let pf = extracted.byClass.get(klass);
-    if (!pf) {
-      const byName = join(dir, `${klass}.md`);
-      if (!extracted.classes.has(klass)) return null;
-      // Class known only via filename/LIBRARY: read the stem file if present.
-      try {
-        const content = await readFile(byName, 'utf8');
-        const dm = DOMAIN_MARKER.exec(content);
-        return { klass, layer, file: byName, content, ...(dm?.[1] ? { domain: dm[1] } : {}) };
-      } catch {
-        return null;
-      }
-    }
-    try {
-      const content = await readFile(pf.file, 'utf8');
-      return { klass, layer, file: pf.file, content, ...(pf.domain ? { domain: pf.domain } : {}) };
-    } catch {
-      return null;
-    }
-  };
 
-  return (
+  // Cached scans are only snapshots. Re-scan immediately before baseline fallback
-    (await fromLayer(overrideDir, over, 'override')) ??
+  // so a newly created canonical or marker-defined override cannot be skipped.
-    (await fromLayer(rolesDir, base, 'baseline'))
+  const currentOver = await extractClassesFromDir(overrideDir);
+  const currentOverride = await readPersonaFromLayer(
+    requested,
+    klass,
+    overrideDir,
+    currentOver,
+    'override',
   );
+  if (currentOverride) return currentOverride;
+  if (overrideShadowsBaseline(currentOver, klass)) return null;
+  if (currentOver.scanState === 'error') return null;
+  return readPersonaFromLayer(requested, klass, rolesDir, base, 'baseline');
 }
 
 /**
@@ -292,40 +543,55 @@ export async function resolvePersonaFrom(
  * one module so the launch-time and command-time resolutions never diverge.
  */
 export function resolvePersonaSync(
-  klass: string,
+  requestedClass: string,
   opts: PersonaDirs = {},
 ): PersonaResolution | null {
+  const { requestedClass: requested, canonicalClass: klass } =
+    canonicalizeRoleClass(requestedClass);
   const { rolesDir, overrideDir } = resolveDirs(opts);
   const base = extractClassesFromDirSync(rolesDir);
   const over = extractClassesFromDirSync(overrideDir);
 
-  const fromLayer = (
+  const override = readPersonaFromLayerSync(requested, klass, overrideDir, over, 'override');
-    dir: string,
+  if (override) return override;
-    extracted: DirClasses,
+  if (overrideShadowsBaseline(over, klass)) return null;
-    layer: PersonaLayer,
+  return readPersonaFromLayerSync(requested, klass, rolesDir, base, 'baseline');
-  ): PersonaResolution | null => {
+}
-    // Prefer the marker-defined file; fall back to the filename stem.
-    const pf = extracted.byClass.get(klass);
-    if (!pf) {
-      if (!extracted.classes.has(klass)) return null;
-      const byName = join(dir, `${klass}.md`);
-      try {
-        const content = readFileSync(byName, 'utf8');
-        const dm = DOMAIN_MARKER.exec(content);
-        return { klass, layer, file: byName, content, ...(dm?.[1] ? { domain: dm[1] } : {}) };
-      } catch {
-        return null;
-      }
-    }
-    try {
-      const content = readFileSync(pf.file, 'utf8');
-      return { klass, layer, file: pf.file, content, ...(pf.domain ? { domain: pf.domain } : {}) };
-    } catch {
-      return null;
-    }
-  };
 
-  return fromLayer(overrideDir, over, 'override') ?? fromLayer(rolesDir, base, 'baseline');
+interface UsablePersonaIndex {
+  personas: Map<string, PersonaResolution>;
+  readableBaseline: Set<string>;
+}
+
+async function collectUsablePersonas(opts: PersonaDirs): Promise<UsablePersonaIndex> {
+  const { rolesDir, overrideDir } = resolveDirs(opts);
+  const [base, over] = await Promise.all([
+    extractClassesFromDir(rolesDir),
+    extractClassesFromDir(overrideDir),
+  ]);
+  if (over.scanState === 'error') {
+    return { personas: new Map(), readableBaseline: new Set() };
+  }
+
+  const candidates = new Set<string>([...base.classes, ...over.classes]);
+  const checked = await Promise.all(
+    [...candidates].map(async (requestedClass) => {
+      const { canonicalClass } = canonicalizeRoleClass(requestedClass);
+      const [persona, baseline] = await Promise.all([
+        resolvePersonaFrom(requestedClass, { rolesDir, overrideDir, base, over }),
+        readPersonaFromLayer(requestedClass, canonicalClass, rolesDir, base, 'baseline'),
+      ]);
+      return { requestedClass, persona, baseline };
+    }),
+  );
+
+  const personas = new Map<string, PersonaResolution>();
+  const readableBaseline = new Set<string>();
+  for (const { requestedClass, persona, baseline } of checked) {
+    if (persona) personas.set(requestedClass, persona);
+    if (baseline) readableBaseline.add(requestedClass);
+  }
+  return { personas, readableBaseline };
 }
 
 export interface PersonaStatusEntry {
@@ -342,24 +608,20 @@ export interface PersonaStatusEntry {
  * Domain is taken from the WINNING layer (override domain wins if present).
  */
 export async function personaStatus(opts: PersonaDirs = {}): Promise<PersonaStatusEntry[]> {
-  const { rolesDir, overrideDir } = resolveDirs(opts);
+  const { personas, readableBaseline } = await collectUsablePersonas(opts);
-  const [base, over] = await Promise.all([
+  const entries = [...personas.entries()].map(([klass, persona]): PersonaStatusEntry => {
-    extractClassesFromDir(rolesDir),
+    const status: PersonaStatus =
-    extractClassesFromDir(overrideDir),
+      persona.layer === 'baseline'
-  ]);
+        ? 'baseline'
-
+        : readableBaseline.has(klass)
-  const all = new Set<string>([...base.classes, ...over.classes]);
+          ? 'overridden'
-  const domainOf = (extracted: DirClasses, klass: string): string | undefined =>
+          : 'custom';
-    extracted.byClass.get(klass)?.domain;
+    return {
-
+      klass,
-  const entries: PersonaStatusEntry[] = [];
+      status,
-  for (const klass of all) {
+      ...(persona.domain ? { domain: persona.domain } : {}),
-    const inBase = base.classes.has(klass);
+    };
-    const inOver = over.classes.has(klass);
+  });
-    const status: PersonaStatus = inOver ? (inBase ? 'overridden' : 'custom') : 'baseline';
-    const domain = (inOver ? domainOf(over, klass) : undefined) ?? domainOf(base, klass);
-    entries.push({ klass, status, ...(domain ? { domain } : {}) });
-  }
   entries.sort((a, b) => a.klass.localeCompare(b.klass));
   return entries;
 }

packages/mosaic/src/commands/fleet-profiles.spec.ts

@@ -203,6 +203,91 @@ describe('loadProfiles with a temp override dir', () => {
     await rm(dir, { recursive: true, force: true });
   });
 
+  it('canonicalizes approved aliases across lead, floor, roster, and topology', async () => {
+    await writeFile(
+      join(dir, 'aliases.yaml'),
+      [
+        'id: aliases',
+        'title: Aliases',
+        'description: legacy class compatibility',
+        'lead: operator-interaction',
+        'floor: [operator-interaction]',
+        'roster:',
+        '  - class: operator-interaction',
+        '  - class: implementer',
+        '    reports_to: operator-interaction',
+        '  - class: reviewer',
+        '    reports_to: operator-interaction',
+        '',
+      ].join('\n'),
+    );
+
+    const profile = await loadProfile('aliases', {
+      profilesDir: dir,
+      rolesDir,
+      overrideDir: join(dir, 'roles.local'),
+    });
+    expect(profile.lead).toBe('interaction');
+    expect(profile.floor).toEqual(['interaction']);
+    expect(profile.roster).toEqual([
+      { class: 'interaction', multiplicity: 1 },
+      { class: 'code', reportsTo: 'interaction', multiplicity: 1 },
+      { class: 'review', reportsTo: 'interaction', multiplicity: 1 },
+    ]);
+  });
+
+  it('rejects roster entries that collapse to the same canonical class', async () => {
+    await writeFile(
+      join(dir, 'alias-collision.yaml'),
+      [
+        'id: alias-collision',
+        'title: Alias collision',
+        'description: ambiguous canonical topology',
+        'lead: orchestrator',
+        'floor: [orchestrator]',
+        'roster:',
+        '  - class: orchestrator',
+        '  - class: code',
+        '    reports_to: orchestrator',
+        '  - class: implementer',
+        '    reports_to: orchestrator',
+        '',
+      ].join('\n'),
+    );
+
+    await expect(
+      loadProfile('alias-collision', {
+        profilesDir: dir,
+        rolesDir,
+        overrideDir: join(dir, 'roles.local'),
+      }),
+    ).rejects.toThrow(/duplicate classes after canonicalization/);
+  });
+
+  it('allows a readable lead or floor persona that is not itself a roster seat', async () => {
+    await writeFile(
+      join(dir, 'external-topology.yaml'),
+      [
+        'id: external-topology',
+        'title: External topology',
+        'description: structural compatibility',
+        'lead: orchestrator',
+        'floor: [enhancer]',
+        'roster:',
+        '  - class: code',
+        '',
+      ].join('\n'),
+    );
+
+    const profile = await loadProfile('external-topology', {
+      profilesDir: dir,
+      rolesDir,
+      overrideDir: join(dir, 'roles.local'),
+    });
+    expect(profile.lead).toBe('orchestrator');
+    expect(profile.floor).toEqual(['enhancer']);
+  });
+
   it('throws when a profile references an unknown class (validated against real roles)', async () => {
     await writeFile(
       join(dir, 'bad.yaml'),

packages/mosaic/src/commands/fleet-profiles.ts

@@ -29,6 +29,7 @@ import {
   defaultOverrideDir,
   extractClassesFromDir,
   listPersonaClasses as listOverrideAwarePersonaClasses,
+  resolvePersonaFrom,
 } from './fleet-personas.js';
 
 function defaultMosaicHome(): string {
@@ -199,6 +200,61 @@ export function validateProfile(profile: FleetProfile, validClasses: Set<string>
   return problems;
 }
 
+export async function resolveProfilePersonas(
+  profile: FleetProfile,
+  rolesDir: string,
+  overrideDir: string,
+): Promise<FleetProfile> {
+  const [base, over] = await Promise.all([
+    extractClassesFromDir(rolesDir),
+    extractClassesFromDir(overrideDir),
+  ]);
+  const requestedClasses = new Set<string>([
+    profile.lead,
+    ...profile.floor,
+    ...profile.roster.flatMap((entry: ProfileRosterEntry): string[] =>
+      entry.reportsTo ? [entry.class, entry.reportsTo] : [entry.class],
+    ),
+  ]);
+  const canonicalByRequested = new Map<string, string>();
+  for (const requestedClass of requestedClasses) {
+    const resolved = await resolvePersonaFrom(requestedClass, {
+      rolesDir,
+      overrideDir,
+      base,
+      over,
+    });
+    if (!resolved || resolved.content.trim() === '') {
+      throw new Error(`persona class "${requestedClass}" does not resolve to a readable persona`);
+    }
+    canonicalByRequested.set(requestedClass, resolved.canonicalClass);
+  }
+  const canonical = (requestedClass: string): string =>
+    canonicalByRequested.get(requestedClass) ?? requestedClass;
+  const roster = profile.roster.map(
+    (entry: ProfileRosterEntry): ProfileRosterEntry => ({
+      class: canonical(entry.class),
+      multiplicity: entry.multiplicity,
+      ...(entry.reportsTo ? { reportsTo: canonical(entry.reportsTo) } : {}),
+    }),
+  );
+  const canonicalRosterClasses = roster.map((entry: ProfileRosterEntry): string => entry.class);
+  if (new Set(canonicalRosterClasses).size !== canonicalRosterClasses.length) {
+    throw new Error('profile roster contains duplicate classes after canonicalization');
+  }
+  const resolvedProfile: FleetProfile = {
+    ...profile,
+    lead: canonical(profile.lead),
+    floor: profile.floor.map(canonical),
+    roster,
+  };
+  const problems = validateProfile(resolvedProfile, new Set(canonicalByRequested.values()));
+  if (problems.length > 0) {
+    throw new Error(problems.join('\n  - '));
+  }
+  return resolvedProfile;
+}
+
 export interface LoadProfilesOptions {
   /** Override the profiles dir (tests). Defaults to <mosaicHome>/fleet/profiles. */
   profilesDir?: string;
@@ -237,10 +293,8 @@ export async function loadProfiles(opts: LoadProfilesOptions = {}): Promise<Flee
   }
   files.sort();
 
-  // Override-aware: a profile may reference a user-customized or user-ADDED
+  // Validation resolves each reference to an actually readable winning persona;
-  // persona living in the roles.local/ layer (H4), so validate against the
+  // LIBRARY membership alone is not semantic success.
-  // baseline ⊕ override union, not the baseline alone.
-  const validClasses = await listPersonaClassesWithOverrides(rolesDir, overrideDir);
   const profiles: FleetProfile[] = [];
   const seen = new Map<string, string>();
 
@@ -255,11 +309,14 @@ export async function loadProfiles(opts: LoadProfilesOptions = {}): Promise<Flee
     }
     seen.set(profile.id, file);
 
-    const problems = validateProfile(profile, validClasses);
+    let resolvedProfile: FleetProfile;
-    if (problems.length > 0) {
+    try {
-      throw new Error(`Profile ${file} is invalid:\n  - ${problems.join('\n  - ')}`);
+      resolvedProfile = await resolveProfilePersonas(profile, rolesDir, overrideDir);
+    } catch (error: unknown) {
+      const detail = error instanceof Error ? error.message : String(error);
+      throw new Error(`Profile ${file} is invalid:\n  - ${detail}`);
     }
-    profiles.push(profile);
+    profiles.push(resolvedProfile);
   }
   return profiles;
 }

packages/mosaic/src/commands/fleet-provision.spec.ts

@@ -172,6 +172,46 @@ describe('override-aware persona validation', () => {
     expect(result.summary).toContain('persona=override');
   });
 
+  it('canonicalizes aliased profile classes and topology identities before emission', async () => {
+    const overrideDir = join(dir, 'roles.local');
+    const customProfilesDir = join(dir, 'profiles');
+    await mkdir(overrideDir, { recursive: true });
+    await mkdir(customProfilesDir, { recursive: true });
+    await writeFile(
+      join(customProfilesDir, 'aliases.yaml'),
+      [
+        'id: aliases',
+        'title: Aliases',
+        'description: legacy aliases',
+        'lead: operator-interaction',
+        'floor: [operator-interaction]',
+        'roster:',
+        '  - class: operator-interaction',
+        '  - class: implementer',
+        '    reports_to: operator-interaction',
+        '  - class: reviewer',
+        '    reports_to: operator-interaction',
+        '',
+      ].join('\n'),
+    );
+
+    const result = await runProvision('aliases', {
+      mosaicHome: dir,
+      profilesDir: customProfilesDir,
+      rolesDir,
+      overrideDir,
+      full: true,
+    });
+    expect(result.yaml).toContain('name: interaction');
+    expect(result.yaml).toContain('class: interaction');
+    expect(result.yaml).toContain('name: code');
+    expect(result.yaml).toContain('class: code');
+    expect(result.yaml).toContain('name: review');
+    expect(result.yaml).toContain('class: review');
+    expect(result.yaml).not.toContain('class: implementer');
+    expect(result.summary).toContain('reports_to=interaction');
+  });
+
   it('FAILS with a clear message when a profile references a bogus class', async () => {
     const customProfilesDir = join(dir, 'profiles');
     await mkdir(customProfilesDir, { recursive: true });

packages/mosaic/src/commands/fleet-provision.ts

@@ -26,12 +26,11 @@ import type { Command } from 'commander';
 import YAML from 'yaml';
 import {
   loadProfile,
-  validateProfile,
   type FleetProfile,
   type ProfileRosterEntry,
   defaultProfilesDir,
   defaultRolesDir,
-  listPersonaClassesWithOverrides,
+  resolveProfilePersonas,
 } from './fleet-profiles.js';
 import {
   defaultOverrideDir,
@@ -201,18 +200,35 @@ export async function generateRoster(
       );
     }
 
-    const runtimeChoice = resolveSeatRuntime(entry.class, isFloor, isLead);
+    const canonicalEntry: ProfileRosterEntry = {
-    for (const name of seatNames(entry)) {
+      class: resolved.canonicalClass,
+      multiplicity: entry.multiplicity,
+      ...(entry.reportsTo
+        ? {
+            reportsTo:
+              (
+                await resolvePersonaFrom(entry.reportsTo, {
+                  rolesDir,
+                  overrideDir,
+                  base,
+                  over,
+                })
+              )?.canonicalClass ?? entry.reportsTo,
+          }
+        : {}),
+    };
+    const runtimeChoice = resolveSeatRuntime(resolved.canonicalClass, isFloor, isLead);
+    for (const name of seatNames(canonicalEntry)) {
       const seat: GeneratedSeat = {
         name,
-        className: entry.class,
+        className: resolved.canonicalClass,
         runtime: runtimeChoice.runtime,
         personaLayer: resolved.layer,
       };
       if (runtimeChoice.modelHint) seat.modelHint = runtimeChoice.modelHint;
       if (isFloor || isLead) seat.persistentPersona = true;
       if (!isFloor && !isLead) seat.resetBetweenTasks = true;
-      if (entry.reportsTo) seat.reportsTo = entry.reportsTo;
+      if (canonicalEntry.reportsTo) seat.reportsTo = canonicalEntry.reportsTo;
       seats.push(seat);
     }
   }
@@ -279,13 +295,7 @@ export async function validateProfileForProvision(
   opts: ProvisionOptions,
 ): Promise<void> {
   const { rolesDir, overrideDir } = resolveDirs(opts);
-  const validClasses = await listPersonaClassesWithOverrides(rolesDir, overrideDir);
+  await resolveProfilePersonas(profile, rolesDir, overrideDir);
-  const problems = validateProfile(profile, validClasses);
-  if (problems.length > 0) {
-    throw new Error(
-      `Profile "${profile.id}" is invalid; cannot provision:\n  - ${problems.join('\n  - ')}`,
-    );
-  }
 }
 
 // ---------------------------------------------------------------------------

packages/mosaic/src/commands/fleet.spec.ts

@@ -1,4 +1,4 @@
-import { mkdir, mkdtemp, readFile, rm, writeFile } from 'node:fs/promises';
+import { chmod, lstat, mkdir, mkdtemp, readFile, rm, stat, writeFile } from 'node:fs/promises';
 import { tmpdir } from 'node:os';
 import { dirname, join, resolve } from 'node:path';
 import { Command } from 'commander';
@@ -284,6 +284,8 @@ describe('fleet roster parsing', () => {
         'MOSAIC_AGENT_CLASS=implementer',
         'MOSAIC_AGENT_RUNTIME=codex',
         'MOSAIC_AGENT_MODEL=',
+        'MOSAIC_AGENT_REASONING=',
+        'MOSAIC_AGENT_TOOL_POLICY=',
         'MOSAIC_AGENT_WORKDIR=/srv/mosaic',
         'MOSAIC_TMUX_SOCKET=mosaic-fleet',
         '',
@@ -325,57 +327,38 @@ describe('fleet roster parsing', () => {
     );
   });
 
-  it('preserves site-owned agent EnvironmentFile overrides while refreshing roster keys', () => {
+  it('rejects legacy command overrides instead of merging them into generated authority', () => {
-    const generated = [
+    const generated = generateAgentEnv(
-      'MOSAIC_AGENT_NAME=coder0',
+      {
-      'MOSAIC_AGENT_RUNTIME=codex',
+        version: 1,
-      'MOSAIC_AGENT_WORKDIR=/srv/new',
+        transport: 'tmux',
-      'MOSAIC_TMUX_SOCKET=mosaic-fleet',
+        tmux: { socketName: 'mosaic-fleet', holderSession: '_holder' },
-      '',
+        defaults: { workingDirectory: '/srv/new' },
-    ].join('\n');
+        runtimes: {},
-    const existing = [
+        agents: [],
-      'MOSAIC_AGENT_NAME=old-name',
+      },
-      'MOSAIC_AGENT_RUNTIME=old-runtime',
+      { name: 'coder0', className: 'code', runtime: 'codex' },
-      'MOSAIC_AGENT_WORKDIR=/srv/old',
+    );
-      'MOSAIC_TMUX_SOCKET=old-socket',
-      'MOSAIC_AGENT_COMMAND=/home/jarvis/.config/mosaic/fleet/canary.sh',
-      '# site note',
-      '',
-    ].join('\n');
 
-    expect(mergeAgentEnv(generated, existing)).toBe(
+    expect((): string => mergeAgentEnv(generated, 'MOSAIC_AGENT_COMMAND=legacy-command\n')).toThrow(
-      [
+      /MOSAIC_AGENT_COMMAND/,
-        'MOSAIC_AGENT_NAME=coder0',
-        'MOSAIC_AGENT_RUNTIME=codex',
-        'MOSAIC_AGENT_WORKDIR=/srv/new',
-        'MOSAIC_TMUX_SOCKET=mosaic-fleet',
-        'MOSAIC_AGENT_COMMAND=/home/jarvis/.config/mosaic/fleet/canary.sh',
-        '# site note',
-        '',
-      ].join('\n'),
     );
   });
 
-  it('updates (does not duplicate) MOSAIC_AGENT_CLASS on re-launch', () => {
+  it('does not merge a valid local value into the generated projection', () => {
-    const generated = [
+    const generated = generateAgentEnv(
-      'MOSAIC_AGENT_NAME=coder0',
+      {
-      'MOSAIC_AGENT_CLASS=orchestrator',
+        version: 1,
-      'MOSAIC_AGENT_RUNTIME=codex',
+        transport: 'tmux',
-      '',
+        tmux: { socketName: 'mosaic-fleet', holderSession: '_holder' },
-    ].join('\n');
+        defaults: { workingDirectory: '/srv/new' },
-    const existing = [
+        runtimes: {},
-      'MOSAIC_AGENT_NAME=coder0',
+        agents: [],
-      'MOSAIC_AGENT_CLASS=worker',
+      },
-      'MOSAIC_AGENT_RUNTIME=codex',
+      { name: 'coder0', className: 'code', runtime: 'codex' },
-      '',
+    );
-    ].join('\n');
 
-    const merged = mergeAgentEnv(generated, existing);
+    expect(mergeAgentEnv(generated, 'MOSAIC_RUNTIME_BIN=/opt/mosaic/bin\n')).toBe(generated);
-    // mergeAgentEnv keys by VAR name, so the regenerated CLASS wins and there is
-    // exactly one MOSAIC_AGENT_CLASS line (no stale worker value left behind).
-    expect(merged).toContain('MOSAIC_AGENT_CLASS=orchestrator');
-    expect(merged).not.toContain('MOSAIC_AGENT_CLASS=worker');
-    expect(merged.match(/^MOSAIC_AGENT_CLASS=/gm)).toHaveLength(1);
   });
 
   it('rejects unknown roster fields instead of silently defaulting', async () => {
@@ -1129,6 +1112,92 @@ describe('fleet command construction', () => {
     }
   });
 
+  it('creates private managed directories and roster/projection files through fresh init and install under umask 022', async () => {
+    const originalHome = process.env.HOME;
+    const originalMosaicHome = process.env.MOSAIC_HOME;
+    const originalUmask = process.umask(0o022);
+    const home = await tempDir();
+    process.env.HOME = home;
+    delete process.env.MOSAIC_HOME;
+    const mosaicHome = join(home, '.config', 'mosaic');
+    const program = new Command();
+    program.exitOverride();
+    registerFleetCommand(program, { frameworkRoot: resolve(process.cwd(), 'framework') });
+
+    try {
+      await expect(
+        program.parseAsync(['node', 'mosaic', 'fleet', 'init', '--profile', 'minimal', '--write']),
+      ).resolves.toBeDefined();
+      await expect(
+        program.parseAsync(['node', 'mosaic', 'fleet', 'install', '--no-enable']),
+      ).resolves.toBeDefined();
+
+      for (const path of [
+        mosaicHome,
+        join(mosaicHome, 'fleet'),
+        join(mosaicHome, 'fleet', 'agents'),
+      ]) {
+        expect((await stat(path)).mode & 0o777).toBe(0o700);
+      }
+      expect((await stat(join(mosaicHome, 'fleet', 'roster.yaml'))).mode & 0o777).toBe(0o600);
+      expect(
+        (await stat(join(mosaicHome, 'fleet', 'agents', 'canary-pi.env.generated'))).mode & 0o777,
+      ).toBe(0o600);
+    } finally {
+      process.umask(originalUmask);
+      if (originalHome === undefined) delete process.env.HOME;
+      else process.env.HOME = originalHome;
+      if (originalMosaicHome === undefined) delete process.env.MOSAIC_HOME;
+      else process.env.MOSAIC_HOME = originalMosaicHome;
+      await rm(home, { recursive: true, force: true });
+    }
+  });
+
+  it('creates a private real projection directory and private generated files on fresh install', async () => {
+    const originalHome = process.env.HOME;
+    const home = await tempDir();
+    process.env.HOME = home;
+    const mosaicHome = join(home, '.config', 'mosaic');
+    const agentEnvDir = join(mosaicHome, 'fleet', 'agents');
+    const fleetDir = join(mosaicHome, 'fleet');
+    await mkdir(fleetDir, { recursive: true, mode: 0o700 });
+    await chmod(mosaicHome, 0o700);
+    await chmod(fleetDir, 0o700);
+    await writeFile(
+      join(mosaicHome, 'fleet', 'roster.yaml'),
+      [
+        'version: 1',
+        'transport: tmux',
+        'agents:',
+        '  - name: coder0',
+        '    runtime: pi',
+        '    class: code',
+      ].join('\n'),
+    );
+    const program = new Command();
+    program.exitOverride();
+    registerFleetCommand(program, {
+      frameworkRoot: resolve(process.cwd(), 'framework'),
+      mosaicHome,
+    });
+
+    try {
+      await expect(
+        program.parseAsync(['node', 'mosaic', 'fleet', 'install', '--no-enable']),
+      ).resolves.toBeDefined();
+
+      const directoryMetadata = await lstat(agentEnvDir);
+      expect(directoryMetadata.isDirectory()).toBe(true);
+      expect(directoryMetadata.isSymbolicLink()).toBe(false);
+      expect(directoryMetadata.mode & 0o777).toBe(0o700);
+      expect((await stat(join(agentEnvDir, 'coder0.env.generated'))).mode & 0o777).toBe(0o600);
+    } finally {
+      if (originalHome === undefined) delete process.env.HOME;
+      else process.env.HOME = originalHome;
+      await rm(home, { recursive: true, force: true });
+    }
+  });
+
   it.each(['start', 'stop', 'restart', 'status'] as const)(
     'rejects single-agent %s for agents outside the roster',
     async (action) => {
@@ -1687,8 +1756,10 @@ describe('fleet ps — drift detection', () => {
 describe('fleet-polish bundle — boot-survival symmetry', () => {
   async function rosterHome(agents: string): Promise<string> {
     const home = await tempDir();
-    await mkdir(join(home, 'fleet'), { recursive: true });
+    const fleetDir = join(home, 'fleet');
-    await writeFile(join(home, 'fleet', 'roster.yaml'), agents);
+    await mkdir(fleetDir, { recursive: true, mode: 0o700 });
+    await chmod(fleetDir, 0o700);
+    await writeFile(join(fleetDir, 'roster.yaml'), agents);
     return home;
   }
 
@@ -3459,7 +3530,11 @@ describe('fleet add command', () => {
 
   async function makeHome(agents = ['orchestrator']): Promise<string> {
     const dir = await mkdtemp(join(tmpdir(), 'mosaic-fleet-add-'));
-    await mkdir(join(dir, 'fleet', 'agents'), { recursive: true });
+    const fleetDir = join(dir, 'fleet');
+    const agentEnvDir = join(fleetDir, 'agents');
+    await mkdir(agentEnvDir, { recursive: true, mode: 0o700 });
+    await chmod(fleetDir, 0o700);
+    await chmod(agentEnvDir, 0o700);
     const agentLines = agents.map((name) => {
       const cls = name === 'orchestrator' ? 'orchestrator' : 'worker';
       return `  - name: ${name}\n    runtime: claude\n    class: ${cls}`;
@@ -3493,11 +3568,110 @@ describe('fleet add command', () => {
     const roster = await loadFleetRoster(join(home, 'fleet', 'roster.yaml'));
     expect(roster.agents.map((a) => a.name)).toContain('coder0');
 
-    const envContent = await readFile(join(home, 'fleet', 'agents', 'coder0.env'), 'utf8');
+    const envContent = await readFile(
+      join(home, 'fleet', 'agents', 'coder0.env.generated'),
+      'utf8',
+    );
     expect(envContent).toContain('MOSAIC_AGENT_NAME=coder0');
     expect(envContent).toContain('MOSAIC_AGENT_RUNTIME=codex');
   });
 
+  it('rejects an unprojectable dogfood runtime without mutating roster or projection state', async () => {
+    home = await makeHome();
+    const rosterPath = join(home, 'fleet', 'roster.yaml');
+    const agentEnvDir = join(home, 'fleet', 'agents');
+    const trackedPaths = [
+      rosterPath,
+      join(agentEnvDir, 'dogfood.env.generated'),
+      join(agentEnvDir, 'dogfood.env.local'),
+      join(agentEnvDir, 'dogfood.env.quarantine'),
+    ];
+    await writeFile(trackedPaths[1]!, 'generated-before\n');
+    await writeFile(trackedPaths[2]!, 'MOSAIC_RUNTIME_BIN=/safe/runtime\n');
+    await writeFile(trackedPaths[3]!, 'quarantine-before\n');
+    const beforeState = new Map<string, Buffer>();
+    for (const path of trackedPaths) beforeState.set(path, await readFile(path));
+
+    const calls: string[][] = [];
+    const runner: CommandRunner = async (command, args) => {
+      calls.push([command, ...args]);
+      return { stdout: '', stderr: '', exitCode: 0 };
+    };
+    const program = new Command();
+    program.exitOverride();
+    registerFleetCommand(program, { runner, mosaicHome: home });
+
+    await expect(
+      program.parseAsync([
+        'node',
+        'mosaic',
+        'fleet',
+        'add',
+        'dogfood',
+        '--runtime',
+        'dogfood',
+        '--class',
+        'worker',
+        '--no-start',
+      ]),
+    ).rejects.toThrow(/runtime/i);
+
+    for (const path of trackedPaths) {
+      expect(await readFile(path)).toEqual(beforeState.get(path));
+    }
+    expect(calls).toEqual([]);
+  });
+
+  it('rejects supported add with a deterministic quarantine conflict before roster persistence', async () => {
+    home = await makeHome();
+    const rosterPath = join(home, 'fleet', 'roster.yaml');
+    const agentEnvDir = join(home, 'fleet', 'agents');
+    const trackedPaths = [
+      rosterPath,
+      join(agentEnvDir, 'coder1.env.generated'),
+      join(agentEnvDir, 'coder1.env.local'),
+      join(agentEnvDir, 'coder1.env'),
+      join(agentEnvDir, 'coder1.env.quarantine'),
+    ];
+    await writeFile(trackedPaths[1]!, 'generated-before\n', { mode: 0o600 });
+    await writeFile(trackedPaths[2]!, 'MOSAIC_RUNTIME_BIN=/safe/runtime\n', { mode: 0o600 });
+    await writeFile(trackedPaths[3]!, 'MOSAIC_AGENT_COMMAND=must-be-quarantined\n', {
+      mode: 0o600,
+    });
+    await writeFile(trackedPaths[4]!, 'quarantine-before\n', { mode: 0o600 });
+    const beforeState = new Map<string, Buffer>();
+    for (const path of trackedPaths) beforeState.set(path, await readFile(path));
+
+    const calls: string[][] = [];
+    const runner: CommandRunner = async (command, args) => {
+      calls.push([command, ...args]);
+      return { stdout: '', stderr: '', exitCode: 0 };
+    };
+    const program = new Command();
+    program.exitOverride();
+    registerFleetCommand(program, { runner, mosaicHome: home });
+
+    await expect(
+      program.parseAsync([
+        'node',
+        'mosaic',
+        'fleet',
+        'add',
+        'coder1',
+        '--runtime',
+        'codex',
+        '--class',
+        'worker',
+        '--no-start',
+      ]),
+    ).rejects.toThrow('quarantine-exists');
+
+    for (const path of trackedPaths) {
+      expect(await readFile(path)).toEqual(beforeState.get(path));
+    }
+    expect(calls).toEqual([]);
+  });
+
   it('--no-start skips the start command', async () => {
     home = await makeHome();
     const calls: string[][] = [];
@@ -3659,7 +3833,10 @@ describe('fleet remove command', () => {
       ].join('\n'),
     );
     // Create env and heartbeat files for coder0
-    await writeFile(join(dir, 'fleet', 'agents', 'coder0.env'), 'MOSAIC_AGENT_NAME=coder0\n');
+    await writeFile(
+      join(dir, 'fleet', 'agents', 'coder0.env.generated'),
+      'MOSAIC_AGENT_NAME=coder0\n',
+    );
     await writeFile(join(dir, 'fleet', 'run', 'coder0.hb'), 'ts=2026-01-01T00:00:00.000Z\n');
     return dir;
   }
@@ -3738,12 +3915,15 @@ describe('fleet remove command', () => {
 
     await program.parseAsync(['node', 'mosaic', 'fleet', 'remove', 'coder0', '--keep-files']);
 
-    // Env file should still exist
+    // Generated projection should still exist.
-    const envContent = await readFile(join(home, 'fleet', 'agents', 'coder0.env'), 'utf8');
+    const envContent = await readFile(
+      join(home, 'fleet', 'agents', 'coder0.env.generated'),
+      'utf8',
+    );
     expect(envContent).toContain('MOSAIC_AGENT_NAME=coder0');
   });
 
-  it('env file is removed by default (no --keep-files)', async () => {
+  it('generated projection is removed by default (no --keep-files)', async () => {
     home = await makeHome();
     const runner: CommandRunner = async () => ({ stdout: '', stderr: '', exitCode: 0 });
     const program = new Command();
@@ -3752,7 +3932,9 @@ describe('fleet remove command', () => {
 
     await program.parseAsync(['node', 'mosaic', 'fleet', 'remove', 'coder0']);
 
-    await expect(readFile(join(home, 'fleet', 'agents', 'coder0.env'), 'utf8')).rejects.toThrow();
+    await expect(
+      readFile(join(home, 'fleet', 'agents', 'coder0.env.generated'), 'utf8'),
+    ).rejects.toThrow();
   });
 
   it('removing the sole orchestrator throws with a clear error about the guard', async () => {

packages/mosaic/src/commands/fleet.ts

@@ -19,6 +19,16 @@ import * as readline from 'node:readline';
 import type { Command } from 'commander';
 import YAML from 'yaml';
 import { resolveCommsBlock } from '../fleet/comms-onboarding.js';
+import {
+  applyPreparedAgentEnvironmentProjection,
+  ensureFleetHolderIdentity,
+  GENERATED_AGENT_ENV_SUPPORTED_RUNTIMES,
+  parseAgentEnvironment,
+  prepareAgentEnvironmentProjection,
+  renderGeneratedAgentEnvironment,
+  writeAgentEnvironmentProjection,
+  writeManagedFleetRoster,
+} from '../fleet/generated-env-boundary.js';
 import { registerFleetBacklogCommand } from './fleet-backlog.js';
 import { registerFleetPersonaCommand } from './fleet-personas.js';
 import { registerFleetProfileCommand } from './fleet-profiles.js';
@@ -509,50 +519,35 @@ export async function generateNorthStarMarkdown(repoRoot?: string): Promise<stri
 }
 
 export function generateAgentEnv(roster: FleetRoster, agent: FleetAgent): string {
-  const workingDirectory = agent.workingDirectory ?? roster.defaults.workingDirectory;
+  return renderGeneratedAgentEnvironment(generateAgentEnvValues(roster, agent));
-  return [
-    `MOSAIC_AGENT_NAME=${shellEnvValue(agent.name)}`,
-    // Per-agent class → start-agent-session.sh / launcher reads this to inject the
-    // matching persona contract for the agent's class (default `worker`).
-    `MOSAIC_AGENT_CLASS=${shellEnvValue(agent.className)}`,
-    `MOSAIC_AGENT_RUNTIME=${shellEnvValue(agent.runtime)}`,
-    // Per-agent model hint → start-agent-session.sh appends `--model <hint>` to
-    // the `mosaic yolo` launch so workers run on the roster's model (e.g. pi on
-    // openai-codex/gpt-5.5:high). Empty when the agent declares no model_hint.
-    `MOSAIC_AGENT_MODEL=${shellEnvValue(agent.modelHint ?? '')}`,
-    ...(agent.reasoningLevel !== undefined
-      ? [`MOSAIC_AGENT_REASONING=${shellEnvValue(agent.reasoningLevel)}`]
-      : []),
-    ...(agent.toolPolicy !== undefined
-      ? [`MOSAIC_AGENT_TOOL_POLICY=${shellEnvValue(agent.toolPolicy)}`]
-      : []),
-    `MOSAIC_AGENT_WORKDIR=${shellEnvValue(expandHome(workingDirectory))}`,
-    `MOSAIC_TMUX_SOCKET=${shellEnvValue(roster.tmux.socketName)}`,
-    '',
-  ].join('\n');
 }
 
+/**
+ * Compatibility shim for callers that previously merged site-owned data into a
+ * generated file. Local data is validated but never appended to the generated
+ * projection, preventing a local override from becoming hidden authority.
+ */
 export function mergeAgentEnv(generatedEnv: string, existingEnv?: string): string {
-  if (!existingEnv?.trim()) {
+  parseAgentEnvironment(generatedEnv, 'generated');
-    return generatedEnv;
+  if (existingEnv?.trim()) parseAgentEnvironment(existingEnv, 'local');
-  }
+  return generatedEnv;
-  const generatedKeys = new Set(
+}
-    generatedEnv
+
-      .split('\n')
+function generateAgentEnvValues(
-      .map((line) => line.match(/^([A-Za-z_][A-Za-z0-9_]*)=/)?.[1])
+  roster: FleetRoster,
-      .filter((key): key is string => key !== undefined),
+  agent: FleetAgent,
-  );
+): Readonly<Record<string, string>> {
-  const preservedLines = existingEnv.split('\n').filter((line) => {
+  const workingDirectory = agent.workingDirectory ?? roster.defaults.workingDirectory;
-    if (!line.trim()) {
+  return {
-      return false;
+    MOSAIC_AGENT_NAME: agent.name,
-    }
+    MOSAIC_AGENT_CLASS: agent.className,
-    const key = line.match(/^([A-Za-z_][A-Za-z0-9_]*)=/)?.[1];
+    MOSAIC_AGENT_RUNTIME: agent.runtime,
-    return key === undefined || !generatedKeys.has(key);
+    MOSAIC_AGENT_MODEL: agent.modelHint ?? '',
-  });
+    MOSAIC_AGENT_REASONING: agent.reasoningLevel ?? '',
-  if (preservedLines.length === 0) {
+    MOSAIC_AGENT_TOOL_POLICY: agent.toolPolicy ?? '',
-    return generatedEnv;
+    MOSAIC_AGENT_WORKDIR: expandHome(workingDirectory),
-  }
+    MOSAIC_TMUX_SOCKET: roster.tmux.socketName,
-  return [generatedEnv.trimEnd(), ...preservedLines, ''].join('\n');
+  };
 }
 
 export function buildFleetServiceCommand(action: FleetServiceAction, agentName?: string): string[] {
@@ -1544,8 +1539,12 @@ export function registerFleetCommand(program: Command, deps: FleetCommandDeps =
           `Fleet roster already exists: ${destination}. Re-run with --force to overwrite.`,
         );
       }
-      await mkdir(dirname(destination), { recursive: true });
+      if (resolve(destination) === resolve(activePaths.rosterPath)) {
-      await writeFile(destination, content);
+        await writeManagedFleetRoster(activePaths.mosaicHome, destination, content);
+      } else {
+        await mkdir(dirname(destination), { recursive: true });
+        await writeFile(destination, content);
+      }
 
       // Guarantee the two-agent floor: exactly one orchestrator AND at least
       // one enhancer for every profile except the sanctioned no-orchestrator
@@ -1948,15 +1947,17 @@ export function registerFleetCommand(program: Command, deps: FleetCommandDeps =
         };
 
         const updatedRoster = addAgentToRoster(roster, newAgent);
+        const generated = generateAgentEnvValues(updatedRoster, newAgent);
+        // Preflight every deterministic projection, local, legacy, quarantine,
+        // and managed-directory condition before roster authority changes.
+        const preparedProjection = await prepareAgentEnvironmentProjection({
+          mosaicHome: activePaths.mosaicHome,
+          agentEnvDir: activePaths.agentEnvDir,
+          agentName: name,
+          generated,
+        });
         await writeFile(rosterPath, serializeRosterToYaml(updatedRoster));
-
+        await applyPreparedAgentEnvironmentProjection(preparedProjection);
-        const envPath = join(activePaths.agentEnvDir, `${name}.env`);
-        const existingEnv = (await canRead(envPath)) ? await readFile(envPath, 'utf8') : undefined;
-        await mkdir(activePaths.agentEnvDir, { recursive: true });
-        await writeFile(
-          envPath,
-          mergeAgentEnv(generateAgentEnv(updatedRoster, newAgent), existingEnv),
-        );
 
         console.log(`Added ${name} (${opts.runtime}/${opts.class}) to the fleet.`);
 
@@ -2037,10 +2038,11 @@ export function registerFleetCommand(program: Command, deps: FleetCommandDeps =
       // Write updated roster
       await writeFile(rosterPath, serializeRosterToYaml(updatedRoster));
 
-      // Delete env and heartbeat files (best-effort, non-fatal)
+      // Delete the non-authoritative generated projection and heartbeat files
+      // (best-effort, non-fatal). Operator local/quarantine data is retained.
       if (!opts.keepFiles) {
         try {
-          await unlink(join(activePaths.agentEnvDir, `${name}.env`));
+          await unlink(join(activePaths.agentEnvDir, `${name}.env.generated`));
         } catch {
           // best-effort
         }
@@ -2328,16 +2330,17 @@ async function installFleet(cmd: Command, frameworkRoot: string): Promise<void>
   const activePaths = resolveFleetPaths(cmd.opts<{ mosaicHome: string }>().mosaicHome);
   assertDefaultMosaicHomeForSystemd(activePaths.mosaicHome);
   const roster = await loadRosterForCommand(cmd);
+  await ensureFleetHolderIdentity(activePaths.mosaicHome);
   await mkdir(activePaths.fleetToolsDir, { recursive: true });
   await mkdir(activePaths.tmuxToolsDir, { recursive: true });
   await mkdir(activePaths.systemdUserDir, { recursive: true });
-  await mkdir(activePaths.agentEnvDir, { recursive: true });
 
   const startAgentSessionPath = join(activePaths.fleetToolsDir, 'start-agent-session.sh');
   const startInteractionServicePath = join(
     activePaths.fleetToolsDir,
     'start-interaction-service.sh',
   );
+  const startTmuxHolderPath = join(activePaths.fleetToolsDir, 'start-tmux-holder.sh');
   const printInteractionPolicyPath = join(
     activePaths.fleetToolsDir,
     'print-interaction-effective-policy.sh',
@@ -2347,6 +2350,7 @@ async function installFleet(cmd: Command, frameworkRoot: string): Promise<void>
   const executableToolPaths = [
     startAgentSessionPath,
     startInteractionServicePath,
+    startTmuxHolderPath,
     printInteractionPolicyPath,
     sendMessagePath,
     agentSendPath,
@@ -2359,6 +2363,10 @@ async function installFleet(cmd: Command, frameworkRoot: string): Promise<void>
     join(frameworkRoot, 'tools', 'fleet', 'start-interaction-service.sh'),
     startInteractionServicePath,
   );
+  await copyFile(
+    join(frameworkRoot, 'tools', 'fleet', 'start-tmux-holder.sh'),
+    startTmuxHolderPath,
+  );
   await copyFile(
     join(frameworkRoot, 'tools', 'fleet', 'print-interaction-effective-policy.sh'),
     printInteractionPolicyPath,
@@ -2382,9 +2390,12 @@ async function installFleet(cmd: Command, frameworkRoot: string): Promise<void>
   );
 
   for (const agent of roster.agents) {
-    const envPath = join(activePaths.agentEnvDir, `${agent.name}.env`);
+    await writeAgentEnvironmentProjection({
-    const existingEnv = (await canRead(envPath)) ? await readFile(envPath, 'utf8') : undefined;
+      mosaicHome: activePaths.mosaicHome,
-    await writeFile(envPath, mergeAgentEnv(generateAgentEnv(roster, agent), existingEnv));
+      agentEnvDir: activePaths.agentEnvDir,
+      agentName: agent.name,
+      generated: generateAgentEnvValues(roster, agent),
+    });
   }
 
   console.log(`Installed fleet files for ${roster.agents.length} agent(s).`);
@@ -2656,19 +2667,6 @@ function expandHome(path: string): string {
   return path === '~' || path.startsWith('~/') ? join(homedir(), path.slice(2)) : path;
 }
 
-function shellEnvValue(value: string): string {
-  // Empty ⇒ a bare `VAR=` (unambiguous empty in a systemd EnvironmentFile and
-  // when shell-sourced). Quoting it as '' risks a literal two-char value (e.g.
-  // a tmux socket named "''"), which would defeat the default-socket behavior.
-  if (value === '') {
-    return '';
-  }
-  if (/^[A-Za-z0-9_./:=@+-]+$/.test(value)) {
-    return value;
-  }
-  return `'${value.replaceAll("'", "'\"'\"'")}'`;
-}
-
 async function stopFleetBestEffort(runner: CommandRunner, agentNames: string[]): Promise<void> {
   const failures: string[] = [];
   for (const agentName of agentNames) {
@@ -2770,13 +2768,8 @@ export function countEnhancers(roster: FleetRoster): number {
 }
 
 /** Valid runtime identifiers for fleet agents. */
-export const VALID_FLEET_RUNTIMES: readonly string[] = [
+/** Runtime launchers accepted by `fleet add`; shared with the generated projection validator. */
-  'pi',
+export const VALID_FLEET_RUNTIMES: readonly string[] = GENERATED_AGENT_ENV_SUPPORTED_RUNTIMES;
-  'claude',
-  'codex',
-  'opencode',
-  'dogfood',
-];
 
 /**
  * Add a new agent to a fleet roster (immutable — returns a new FleetRoster).

packages/mosaic/src/fleet/example-profile-dispositions.spec.ts

@@ -0,0 +1,90 @@
+import { cp, mkdtemp, readFile, rm, writeFile } from 'node:fs/promises';
+import { tmpdir } from 'node:os';
+import { dirname, join, resolve } from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { afterEach, describe, expect, it } from 'vitest';
+import {
+  SHIPPED_FLEET_ARTIFACT_DISPOSITIONS,
+  validateShippedFleetArtifactDispositions,
+} from './example-profile-dispositions.js';
+
+const frameworkFleet = resolve(
+  dirname(fileURLToPath(import.meta.url)),
+  '..',
+  '..',
+  'framework',
+  'fleet',
+);
+
+const EXPECTED_DISPOSITIONS = [
+  'examples/coding.yaml:v1-fixture',
+  'examples/general.yaml:v1-fixture',
+  'examples/hybrid.yaml:v1-fixture',
+  'examples/local-canary.yaml:v1-fixture',
+  'examples/minimal.yaml:v1-fixture',
+  'examples/operator-interaction.yaml:v1-fixture',
+  'examples/research.yaml:v1-fixture',
+  'profiles/business.yaml:canonical-profile',
+  'profiles/marketing.yaml:canonical-profile',
+  'profiles/personal-assistant.yaml:canonical-profile',
+  'profiles/research.yaml:canonical-profile',
+  'profiles/software-delivery.yaml:canonical-profile',
+  'services/operator-interaction.yaml:canonical-service-policy',
+];
+
+const declared = SHIPPED_FLEET_ARTIFACT_DISPOSITIONS.map(
+  ({ path, disposition }): string => `${path}:${disposition}`,
+);
+
+describe('shipped fleet example/profile/service disposition validation', (): void => {
+  it('enumerates every inventory artifact with an explicit executable disposition', (): void => {
+    expect(declared).toEqual(EXPECTED_DISPOSITIONS);
+  });
+
+  it('validates every shipped artifact through its declared v1 or canonical path', async (): Promise<void> => {
+    const results = await validateShippedFleetArtifactDispositions({ frameworkFleet });
+
+    expect(results.map(({ path, disposition }): string => `${path}:${disposition}`)).toEqual(
+      EXPECTED_DISPOSITIONS,
+    );
+    expect(results.filter(({ disposition }): boolean => disposition === 'v1-fixture')).toHaveLength(
+      7,
+    );
+    expect(
+      results.filter(({ disposition }): boolean => disposition === 'canonical-profile'),
+    ).toHaveLength(5);
+    expect(
+      results.find(({ path }): boolean => path === 'services/operator-interaction.yaml'),
+    ).toMatchObject({
+      disposition: 'canonical-service-policy',
+    });
+  });
+
+  let temporaryFleet: string | undefined;
+  afterEach(async (): Promise<void> => {
+    if (temporaryFleet) await rm(temporaryFleet, { recursive: true, force: true });
+    temporaryFleet = undefined;
+  });
+
+  it('fails closed when a shipped artifact lacks a declared disposition', async (): Promise<void> => {
+    temporaryFleet = await mkdtemp(join(tmpdir(), 'mosaic-dispositions-'));
+    await cp(frameworkFleet, temporaryFleet, { recursive: true });
+    await writeFile(join(temporaryFleet, 'examples', 'undeclared.yaml'), 'version: 1\n');
+
+    await expect(
+      validateShippedFleetArtifactDispositions({ frameworkFleet: temporaryFleet }),
+    ).rejects.toThrow(/undeclared shipped fleet artifact.*examples\/undeclared.yaml/i);
+  });
+
+  it('rejects a v1 fixture when its explicit version declaration is removed', async (): Promise<void> => {
+    temporaryFleet = await mkdtemp(join(tmpdir(), 'mosaic-dispositions-'));
+    await cp(frameworkFleet, temporaryFleet, { recursive: true });
+    const fixturePath = join(temporaryFleet, 'examples', 'coding.yaml');
+    const fixture = await readFile(fixturePath, 'utf8');
+    await writeFile(fixturePath, fixture.replace(/^version: 1\n/, ''));
+
+    await expect(
+      validateShippedFleetArtifactDispositions({ frameworkFleet: temporaryFleet }),
+    ).rejects.toThrow(/Fleet roster version must be 1/);
+  });
+});

packages/mosaic/src/fleet/example-profile-dispositions.ts

@@ -0,0 +1,121 @@
+import { readdir } from 'node:fs/promises';
+import { basename, join } from 'node:path';
+import { loadFleetRoster } from '../commands/fleet.js';
+import { loadProfiles } from '../commands/fleet-profiles.js';
+import {
+  provisionInteractionService,
+  readInteractionServiceProfile,
+} from './interaction-service-profile.js';
+
+export type FleetArtifactDisposition =
+  | 'v1-fixture'
+  | 'canonical-profile'
+  | 'canonical-service-policy';
+
+export interface ShippedFleetArtifactDisposition {
+  readonly path: string;
+  readonly disposition: FleetArtifactDisposition;
+}
+
+export interface ValidateShippedFleetArtifactDispositionsOptions {
+  readonly frameworkFleet: string;
+  readonly rolesDir?: string;
+  readonly overrideDir?: string;
+}
+
+/**
+ * The M0 inventory in executable form. Every shipped fleet YAML asset is either
+ * a deliberately retained v1 fixture or validated through its canonical loader.
+ */
+export const SHIPPED_FLEET_ARTIFACT_DISPOSITIONS: readonly ShippedFleetArtifactDisposition[] = [
+  { path: 'examples/coding.yaml', disposition: 'v1-fixture' },
+  { path: 'examples/general.yaml', disposition: 'v1-fixture' },
+  { path: 'examples/hybrid.yaml', disposition: 'v1-fixture' },
+  { path: 'examples/local-canary.yaml', disposition: 'v1-fixture' },
+  { path: 'examples/minimal.yaml', disposition: 'v1-fixture' },
+  { path: 'examples/operator-interaction.yaml', disposition: 'v1-fixture' },
+  { path: 'examples/research.yaml', disposition: 'v1-fixture' },
+  { path: 'profiles/business.yaml', disposition: 'canonical-profile' },
+  { path: 'profiles/marketing.yaml', disposition: 'canonical-profile' },
+  { path: 'profiles/personal-assistant.yaml', disposition: 'canonical-profile' },
+  { path: 'profiles/research.yaml', disposition: 'canonical-profile' },
+  { path: 'profiles/software-delivery.yaml', disposition: 'canonical-profile' },
+  { path: 'services/operator-interaction.yaml', disposition: 'canonical-service-policy' },
+];
+
+/**
+ * Fail closed when a fleet YAML asset is added or removed without a disposition.
+ * This keeps legacy v1 compatibility explicit instead of silently accepting new
+ * unresolved classes outside the shared resolver.
+ */
+export async function validateShippedFleetArtifactDispositions(
+  options: ValidateShippedFleetArtifactDispositionsOptions,
+): Promise<readonly ShippedFleetArtifactDisposition[]> {
+  await assertEveryShippedArtifactIsDeclared(options.frameworkFleet);
+
+  const examples = SHIPPED_FLEET_ARTIFACT_DISPOSITIONS.filter(
+    ({ disposition }): boolean => disposition === 'v1-fixture',
+  );
+  for (const artifact of examples) {
+    const roster = await loadFleetRoster(join(options.frameworkFleet, artifact.path));
+    if (roster.version !== 1) {
+      throw new Error(`v1 fixture ${artifact.path} must declare version: 1`);
+    }
+  }
+
+  const profilesDir = join(options.frameworkFleet, 'profiles');
+  const profiles = await loadProfiles({
+    profilesDir,
+    rolesDir: options.rolesDir ?? join(options.frameworkFleet, 'roles'),
+    overrideDir: options.overrideDir ?? join(options.frameworkFleet, 'roles.local'),
+  });
+  const declaredProfiles = SHIPPED_FLEET_ARTIFACT_DISPOSITIONS.filter(
+    ({ disposition }): boolean => disposition === 'canonical-profile',
+  ).map(({ path }): string => basename(path, '.yaml'));
+  const resolvedProfiles = new Set(profiles.map(({ id }): string => id));
+  for (const profileId of declaredProfiles) {
+    if (!resolvedProfiles.has(profileId)) {
+      throw new Error(`declared canonical profile ${profileId} did not resolve`);
+    }
+  }
+
+  const servicePolicies = SHIPPED_FLEET_ARTIFACT_DISPOSITIONS.filter(
+    ({ disposition }): boolean => disposition === 'canonical-service-policy',
+  );
+  for (const artifact of servicePolicies) {
+    const serviceProfile = await readInteractionServiceProfile(
+      join(options.frameworkFleet, artifact.path),
+    );
+    provisionInteractionService(serviceProfile, { agentName: 'interaction-example' });
+  }
+
+  return SHIPPED_FLEET_ARTIFACT_DISPOSITIONS;
+}
+
+async function assertEveryShippedArtifactIsDeclared(frameworkFleet: string): Promise<void> {
+  const declared = new Set(SHIPPED_FLEET_ARTIFACT_DISPOSITIONS.map(({ path }): string => path));
+  const shipped = await listShippedFleetArtifactPaths(frameworkFleet);
+
+  for (const path of shipped) {
+    if (!declared.has(path)) {
+      throw new Error(`undeclared shipped fleet artifact: ${path}`);
+    }
+  }
+  for (const path of declared) {
+    if (!shipped.has(path)) {
+      throw new Error(`declared shipped fleet artifact is missing: ${path}`);
+    }
+  }
+}
+
+async function listShippedFleetArtifactPaths(frameworkFleet: string): Promise<Set<string>> {
+  const directories = ['examples', 'profiles', 'services'];
+  const paths = new Set<string>();
+  for (const directory of directories) {
+    const files = await readdir(join(frameworkFleet, directory));
+    for (const file of files) {
+      if (file.endsWith('.yaml') || file.endsWith('.yml')) paths.add(`${directory}/${file}`);
+    }
+  }
+  return paths;
+}

packages/mosaic/src/fleet/generated-env-boundary.spec.ts

@@ -0,0 +1,279 @@
+import {
+  chmod,
+  mkdir,
+  mkdtemp,
+  readFile,
+  rename,
+  rm,
+  stat,
+  symlink,
+  writeFile,
+} from 'node:fs/promises';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+import { afterEach, describe, expect, it } from 'vitest';
+import {
+  AgentEnvBoundaryError,
+  parseAgentEnvironment,
+  renderGeneratedAgentEnvironment,
+  writeAgentEnvironmentProjection,
+} from './generated-env-boundary.js';
+
+const generatedValues = {
+  MOSAIC_AGENT_NAME: 'coder0',
+  MOSAIC_AGENT_CLASS: 'code',
+  MOSAIC_AGENT_RUNTIME: 'pi',
+  MOSAIC_AGENT_MODEL: 'openai-codex/gpt-5.6-sol',
+  MOSAIC_AGENT_REASONING: 'high',
+  MOSAIC_AGENT_TOOL_POLICY: 'code',
+  MOSAIC_AGENT_WORKDIR: '/srv/mosaic',
+  MOSAIC_TMUX_SOCKET: 'mosaic-fleet',
+};
+
+describe('generated fleet agent environment boundary', (): void => {
+  let cleanup: string | undefined;
+
+  afterEach(async (): Promise<void> => {
+    if (cleanup) {
+      await rm(cleanup, { recursive: true, force: true });
+      cleanup = undefined;
+    }
+  });
+
+  it('renders a deterministic complete generated projection', (): void => {
+    expect(renderGeneratedAgentEnvironment(generatedValues)).toBe(
+      [
+        'MOSAIC_AGENT_NAME=coder0',
+        'MOSAIC_AGENT_CLASS=code',
+        'MOSAIC_AGENT_RUNTIME=pi',
+        'MOSAIC_AGENT_MODEL=openai-codex/gpt-5.6-sol',
+        'MOSAIC_AGENT_REASONING=high',
+        'MOSAIC_AGENT_TOOL_POLICY=code',
+        'MOSAIC_AGENT_WORKDIR=/srv/mosaic',
+        'MOSAIC_TMUX_SOCKET=mosaic-fleet',
+        '',
+      ].join('\n'),
+    );
+  });
+
+  it.each([
+    ['generated-key shadowing', 'MOSAIC_AGENT_RUNTIME=codex\n'],
+    ['unknown key', 'UNRELATED_SETTING=value\n'],
+    ['arbitrary command', 'MOSAIC_AGENT_COMMAND=mosaic yolo codex\n'],
+    ['sensitive key', 'MOSAIC_AGENT_TOKEN=do-not-log-me\n'],
+    ['malformed syntax', 'export MOSAIC_RUNTIME_BIN=/opt/bin\n'],
+    ['duplicate keys', 'MOSAIC_RUNTIME_BIN=/opt/bin\nMOSAIC_RUNTIME_BIN=/other/bin\n'],
+  ])('rejects local %s without echoing values', (_name: string, source: string): void => {
+    let error: unknown;
+    try {
+      parseAgentEnvironment(source, 'local');
+    } catch (caught: unknown) {
+      error = caught;
+    }
+
+    expect(error).toBeInstanceOf(AgentEnvBoundaryError);
+    expect(String(error)).not.toContain('mosaic yolo codex');
+    expect(String(error)).not.toContain('do-not-log-me');
+    expect(String(error)).toMatch(/key=.*sha256=/);
+  });
+
+  it('rejects unsafe generated paths before any launch consumer can use them', (): void => {
+    expect((): void => {
+      renderGeneratedAgentEnvironment({
+        ...generatedValues,
+        MOSAIC_AGENT_WORKDIR: '../outside',
+      });
+    }).toThrow(AgentEnvBoundaryError);
+  });
+
+  it('creates missing managed directories privately before writing a projection', async (): Promise<void> => {
+    cleanup = await mkdtemp(join(tmpdir(), 'mosaic-generated-env-'));
+    const mosaicHome = join(cleanup, 'mosaic');
+    const agentEnvDir = join(mosaicHome, 'fleet', 'agents');
+
+    const result = await writeAgentEnvironmentProjection({
+      mosaicHome,
+      agentEnvDir,
+      agentName: 'coder0',
+      generated: generatedValues,
+    });
+
+    for (const directory of [mosaicHome, join(mosaicHome, 'fleet'), agentEnvDir]) {
+      expect((await stat(directory)).mode & 0o777).toBe(0o700);
+    }
+    expect((await stat(result.generatedPath)).mode & 0o777).toBe(0o600);
+  });
+
+  it('regenerates desired keys, relocates safe legacy local data, and quarantines forbidden legacy input', async (): Promise<void> => {
+    cleanup = await mkdtemp(join(tmpdir(), 'mosaic-generated-env-'));
+    const mosaicHome = join(cleanup, 'mosaic');
+    const agentEnvDir = join(mosaicHome, 'fleet', 'agents');
+    await mkdir(agentEnvDir, { recursive: true, mode: 0o700 });
+    await writeFile(
+      join(agentEnvDir, 'coder0.env'),
+      [
+        'MOSAIC_AGENT_NAME=stale-name',
+        'MOSAIC_AGENT_RUNTIME=codex',
+        'MOSAIC_RUNTIME_BIN=/opt/mosaic/bin',
+        'MOSAIC_AGENT_COMMAND=mosaic yolo codex --dangerous',
+        '',
+      ].join('\n'),
+      { mode: 0o600 },
+    );
+
+    const result = await writeAgentEnvironmentProjection({
+      mosaicHome,
+      agentEnvDir,
+      agentName: 'coder0',
+      generated: generatedValues,
+    });
+
+    expect(await readFile(result.generatedPath, 'utf8')).toBe(
+      renderGeneratedAgentEnvironment(generatedValues),
+    );
+    expect(await readFile(result.localPath, 'utf8')).toBe('MOSAIC_RUNTIME_BIN=/opt/mosaic/bin\n');
+    const quarantine = await readFile(result.quarantinePath!, 'utf8');
+    expect(quarantine).toContain('MOSAIC_AGENT_COMMAND=mosaic yolo codex --dangerous');
+    await expect(readFile(join(agentEnvDir, 'coder0.env'), 'utf8')).rejects.toThrow();
+    expect((await stat(result.generatedPath)).mode & 0o077).toBe(0);
+    expect((await stat(result.localPath)).mode & 0o077).toBe(0);
+    expect(result.diagnostics).toEqual([expect.objectContaining({ key: 'MOSAIC_AGENT_COMMAND' })]);
+    expect(JSON.stringify(result.diagnostics)).not.toContain('mosaic yolo codex --dangerous');
+  });
+
+  it('fails closed on an existing local override with unsafe permissions', async (): Promise<void> => {
+    cleanup = await mkdtemp(join(tmpdir(), 'mosaic-generated-env-'));
+    const mosaicHome = join(cleanup, 'mosaic');
+    const agentEnvDir = join(mosaicHome, 'fleet', 'agents');
+    await mkdir(agentEnvDir, { recursive: true, mode: 0o700 });
+    const localPath = join(agentEnvDir, 'coder0.env.local');
+    await writeFile(localPath, 'MOSAIC_RUNTIME_BIN=/opt/mosaic/bin\n', { mode: 0o600 });
+    await chmod(localPath, 0o644);
+
+    await expect(
+      writeAgentEnvironmentProjection({
+        mosaicHome,
+        agentEnvDir,
+        agentName: 'coder0',
+        generated: generatedValues,
+      }),
+    ).rejects.toThrow(/permissions/i);
+  });
+
+  it('rejects an existing group/world-accessible projection directory before reading it', async (): Promise<void> => {
+    cleanup = await mkdtemp(join(tmpdir(), 'mosaic-generated-env-'));
+    const mosaicHome = join(cleanup, 'mosaic');
+    const agentEnvDir = join(mosaicHome, 'fleet', 'agents');
+    const localPath = join(agentEnvDir, 'coder0.env.local');
+    const generatedPath = join(agentEnvDir, 'coder0.env.generated');
+    await mkdir(agentEnvDir, { recursive: true, mode: 0o700 });
+    await writeFile(localPath, 'MOSAIC_RUNTIME_BIN=/opt/mosaic/bin\n', { mode: 0o600 });
+    await chmod(agentEnvDir, 0o777);
+
+    await expect(
+      writeAgentEnvironmentProjection({
+        mosaicHome,
+        agentEnvDir,
+        agentName: 'coder0',
+        generated: generatedValues,
+      }),
+    ).rejects.toThrow(/unsafe-permissions/i);
+
+    await expect(readFile(localPath, 'utf8')).resolves.toBe('MOSAIC_RUNTIME_BIN=/opt/mosaic/bin\n');
+    await expect(readFile(generatedPath, 'utf8')).rejects.toThrow();
+  });
+
+  it.each([
+    ['MOSAIC_HOME', 'symlink'],
+    ['MOSAIC_HOME/fleet', 'symlink'],
+    ['MOSAIC_HOME/fleet/agents', 'symlink'],
+    ['MOSAIC_HOME', 'group/world-writable'],
+    ['MOSAIC_HOME/fleet', 'group/world-writable'],
+    ['MOSAIC_HOME/fleet/agents', 'group/world-writable'],
+  ])(
+    'rejects a %s %s managed ancestor before any projection mutation',
+    async (ancestor: string, hazard: string): Promise<void> => {
+      cleanup = await mkdtemp(join(tmpdir(), 'mosaic-generated-env-'));
+      const mosaicHome = join(cleanup, 'mosaic');
+      const fleetDir = join(mosaicHome, 'fleet');
+      const agentEnvDir = join(fleetDir, 'agents');
+      const generatedPath = join(agentEnvDir, 'coder0.env.generated');
+      const localPath = join(agentEnvDir, 'coder0.env.local');
+      const legacyPath = join(agentEnvDir, 'coder0.env');
+      const quarantinePath = join(agentEnvDir, 'coder0.env.quarantine');
+      const managedPaths: Record<string, string> = {
+        MOSAIC_HOME: mosaicHome,
+        'MOSAIC_HOME/fleet': fleetDir,
+        'MOSAIC_HOME/fleet/agents': agentEnvDir,
+      };
+      const unsafePath = managedPaths[ancestor];
+      if (unsafePath === undefined) throw new Error(`Unknown managed ancestor: ${ancestor}`);
+
+      await mkdir(agentEnvDir, { recursive: true, mode: 0o700 });
+      await chmod(mosaicHome, 0o700);
+      await chmod(fleetDir, 0o700);
+      await chmod(agentEnvDir, 0o700);
+      await writeFile(generatedPath, 'generated-before\n', { mode: 0o600 });
+      await writeFile(localPath, 'MOSAIC_RUNTIME_BIN=/safe/runtime\n', { mode: 0o600 });
+      await writeFile(legacyPath, 'MOSAIC_AGENT_COMMAND=legacy-command\n', { mode: 0o600 });
+
+      if (hazard === 'symlink') {
+        const targetPath = `${unsafePath}-target`;
+        await rename(unsafePath, targetPath);
+        await symlink(targetPath, unsafePath, 'dir');
+      } else {
+        await chmod(unsafePath, 0o777);
+      }
+
+      await expect(
+        writeAgentEnvironmentProjection({
+          mosaicHome,
+          agentEnvDir,
+          agentName: 'coder0',
+          generated: generatedValues,
+        }),
+      ).rejects.toThrow(/unsafe-(directory|permissions)/i);
+
+      await expect(readFile(generatedPath, 'utf8')).resolves.toBe('generated-before\n');
+      await expect(readFile(localPath, 'utf8')).resolves.toBe('MOSAIC_RUNTIME_BIN=/safe/runtime\n');
+      await expect(readFile(legacyPath, 'utf8')).resolves.toBe(
+        'MOSAIC_AGENT_COMMAND=legacy-command\n',
+      );
+      await expect(readFile(quarantinePath, 'utf8')).rejects.toThrow();
+    },
+  );
+
+  it('rejects a symlinked projection directory without mutating its target', async (): Promise<void> => {
+    cleanup = await mkdtemp(join(tmpdir(), 'mosaic-generated-env-'));
+    const mosaicHome = join(cleanup, 'mosaic');
+    const targetDirectory = join(cleanup, 'target');
+    const linkedDirectory = join(mosaicHome, 'fleet', 'agents');
+    const legacyPath = join(targetDirectory, 'coder0.env');
+    const generatedPath = join(targetDirectory, 'coder0.env.generated');
+    const localPath = join(targetDirectory, 'coder0.env.local');
+    const quarantinePath = join(targetDirectory, 'coder0.env.quarantine');
+    await mkdir(join(mosaicHome, 'fleet'), { recursive: true, mode: 0o700 });
+    await mkdir(targetDirectory, { mode: 0o700 });
+    await writeFile(legacyPath, 'MOSAIC_AGENT_COMMAND=legacy-command\n', { mode: 0o600 });
+    await writeFile(generatedPath, 'generated-before\n', { mode: 0o600 });
+    await writeFile(localPath, 'local-before\n', { mode: 0o600 });
+    await writeFile(quarantinePath, 'quarantine-before\n', { mode: 0o600 });
+    await symlink(targetDirectory, linkedDirectory, 'dir');
+
+    await expect(
+      writeAgentEnvironmentProjection({
+        mosaicHome,
+        agentEnvDir: linkedDirectory,
+        agentName: 'coder0',
+        generated: generatedValues,
+      }),
+    ).rejects.toThrow(/unsafe-directory/i);
+
+    await expect(readFile(legacyPath, 'utf8')).resolves.toBe(
+      'MOSAIC_AGENT_COMMAND=legacy-command\n',
+    );
+    await expect(readFile(generatedPath, 'utf8')).resolves.toBe('generated-before\n');
+    await expect(readFile(localPath, 'utf8')).resolves.toBe('local-before\n');
+    await expect(readFile(quarantinePath, 'utf8')).resolves.toBe('quarantine-before\n');
+  });
+});

packages/mosaic/src/fleet/generated-env-boundary.ts

@@ -0,0 +1,509 @@
+import { createHash, randomUUID } from 'node:crypto';
+import { chmod, lstat, mkdir, readFile, rename, unlink, writeFile } from 'node:fs/promises';
+import { dirname, join, resolve } from 'node:path';
+
+export type AgentEnvironmentKind = 'generated' | 'local';
+
+export interface AgentEnvironmentDiagnostic {
+  readonly code: string;
+  readonly key: string;
+  readonly sha256: string;
+}
+
+export interface AgentEnvironmentProjectionOptions {
+  readonly mosaicHome: string;
+  readonly agentEnvDir: string;
+  readonly agentName: string;
+  readonly generated: Readonly<Record<string, string>>;
+}
+
+export interface AgentEnvironmentProjectionResult {
+  readonly generatedPath: string;
+  readonly localPath: string;
+  readonly quarantinePath?: string;
+  readonly diagnostics: readonly AgentEnvironmentDiagnostic[];
+}
+
+/** A projection fully validated without changing managed files. */
+export interface PreparedAgentEnvironmentProjection {
+  readonly mosaicHome: string;
+  readonly agentEnvDir: string;
+  readonly generatedPath: string;
+  readonly localPath: string;
+  readonly legacyPath: string;
+  readonly generated: string;
+  readonly local: string;
+  readonly legacy?: string;
+  readonly quarantinePath?: string;
+  readonly diagnostics: readonly AgentEnvironmentDiagnostic[];
+}
+
+export class AgentEnvBoundaryError extends Error {
+  readonly diagnostic: AgentEnvironmentDiagnostic;
+
+  constructor(code: string, key: string, value: string) {
+    const diagnostic: AgentEnvironmentDiagnostic = {
+      code,
+      key,
+      sha256: hashValue(value),
+    };
+    super(`Agent environment rejected: code=${code} key=${key} sha256=${diagnostic.sha256}`);
+    this.name = 'AgentEnvBoundaryError';
+    this.diagnostic = diagnostic;
+  }
+}
+
+export const GENERATED_AGENT_ENV_KEYS = [
+  'MOSAIC_AGENT_NAME',
+  'MOSAIC_AGENT_CLASS',
+  'MOSAIC_AGENT_RUNTIME',
+  'MOSAIC_AGENT_MODEL',
+  'MOSAIC_AGENT_REASONING',
+  'MOSAIC_AGENT_TOOL_POLICY',
+  'MOSAIC_AGENT_WORKDIR',
+  'MOSAIC_TMUX_SOCKET',
+] as const;
+
+export const LOCAL_AGENT_ENV_KEYS = [
+  'MOSAIC_RUNTIME_BIN',
+  'MOSAIC_HEARTBEAT_RUN_DIR',
+  'MOSAIC_HEARTBEAT_INTERVAL',
+  'MOSAIC_CLAUDE_JSON',
+  'CLAUDE_CONFIG_DIR',
+] as const;
+
+const GENERATED_KEY_SET = new Set<string>(GENERATED_AGENT_ENV_KEYS);
+const LOCAL_KEY_SET = new Set<string>(LOCAL_AGENT_ENV_KEYS);
+const SENSITIVE_KEY = /(?:API[_-]?KEY|AUTH|CREDENTIAL|PASSWORD|PRIVATE|SECRET|TOKEN)/i;
+const AGENT_NAME = /^[A-Za-z0-9][A-Za-z0-9_.-]*$/;
+const POLICY_NAME = /^[a-z][a-z0-9-]*$/;
+const TMUX_SOCKET = /^[A-Za-z0-9_.-]*$/;
+const MODEL = /^[A-Za-z0-9._/:+-]*$/;
+/** Runtime launchers supported by the generated environment contract. */
+export const GENERATED_AGENT_ENV_SUPPORTED_RUNTIMES = [
+  'claude',
+  'codex',
+  'opencode',
+  'pi',
+] as const;
+
+const SUPPORTED_RUNTIMES = new Set<string>(GENERATED_AGENT_ENV_SUPPORTED_RUNTIMES);
+const REASONING = new Set(['', 'low', 'medium', 'high']);
+
+/** Parses a strict data-only generated or local environment file without shell evaluation. */
+export function parseAgentEnvironment(
+  source: string,
+  kind: AgentEnvironmentKind,
+): Readonly<Record<string, string>> {
+  const values: Record<string, string> = {};
+  const seen = new Set<string>();
+
+  for (const line of source.split('\n')) {
+    if (line === '') continue;
+    const match = /^([A-Z][A-Z0-9_]*)=(.*)$/.exec(line);
+    if (!match) throw new AgentEnvBoundaryError('malformed-line', '(malformed)', line);
+
+    const [, key, value] = match;
+    if (key === undefined || value === undefined) {
+      throw new AgentEnvBoundaryError('malformed-line', '(malformed)', line);
+    }
+    if (seen.has(key)) throw new AgentEnvBoundaryError('duplicate-key', key, value);
+    seen.add(key);
+    if (SENSITIVE_KEY.test(key)) throw new AgentEnvBoundaryError('sensitive-key', key, value);
+    if (containsShellSyntax(value)) throw new AgentEnvBoundaryError('unsafe-value', key, value);
+
+    if (kind === 'generated') {
+      if (!GENERATED_KEY_SET.has(key)) throw new AgentEnvBoundaryError('unknown-key', key, value);
+    } else {
+      if (GENERATED_KEY_SET.has(key))
+        throw new AgentEnvBoundaryError('generated-key-shadow', key, value);
+      if (!LOCAL_KEY_SET.has(key)) throw new AgentEnvBoundaryError('unknown-key', key, value);
+    }
+    values[key] = value;
+  }
+
+  if (kind === 'generated') assertGeneratedValues(values);
+  else assertLocalValues(values);
+  return Object.freeze(values);
+}
+
+/** Renders the roster-derived generated projection in a stable, complete key order. */
+export function renderGeneratedAgentEnvironment(values: Readonly<Record<string, string>>): string {
+  const normalized = normalizeGeneratedValues(values);
+  return `${GENERATED_AGENT_ENV_KEYS.map((key): string => `${key}=${normalized[key]}`).join('\n')}\n`;
+}
+
+/** Validates all deterministic projection inputs and target state without mutation. */
+export async function prepareAgentEnvironmentProjection(
+  options: AgentEnvironmentProjectionOptions,
+): Promise<PreparedAgentEnvironmentProjection> {
+  if (!AGENT_NAME.test(options.agentName)) {
+    throw new AgentEnvBoundaryError('unsafe-agent-name', 'MOSAIC_AGENT_NAME', options.agentName);
+  }
+
+  await validatePrivateProjectionDirectory(options.mosaicHome, options.agentEnvDir);
+  const generatedPath = join(options.agentEnvDir, `${options.agentName}.env.generated`);
+  const localPath = join(options.agentEnvDir, `${options.agentName}.env.local`);
+  const legacyPath = join(options.agentEnvDir, `${options.agentName}.env`);
+  const generated = renderGeneratedAgentEnvironment(options.generated);
+  await assertPrivateRegularFileIfPresent(generatedPath);
+  const currentLocal = await readOptionalPrivateFile(localPath);
+  const parsedLocal =
+    currentLocal === undefined ? {} : parseAgentEnvironment(currentLocal, 'local');
+  const legacy = await readOptionalPrivateFile(legacyPath);
+  const legacyDisposition =
+    legacy === undefined ? emptyLegacyDisposition() : classifyLegacyEnvironment(legacy);
+
+  for (const [key, value] of Object.entries(legacyDisposition.localValues)) {
+    if (parsedLocal[key] !== undefined && parsedLocal[key] !== value) {
+      throw new AgentEnvBoundaryError('legacy-local-conflict', key, value);
+    }
+  }
+
+  const local = renderLocalAgentEnvironment({ ...legacyDisposition.localValues, ...parsedLocal });
+  const quarantinePath = legacyDisposition.diagnostics.length
+    ? join(options.agentEnvDir, `${options.agentName}.env.quarantine`)
+    : undefined;
+  if (quarantinePath !== undefined) {
+    const existingQuarantine = await readOptionalPrivateFile(quarantinePath);
+    if (existingQuarantine !== undefined) {
+      throw new AgentEnvBoundaryError('quarantine-exists', '(quarantine)', existingQuarantine);
+    }
+  }
+
+  return {
+    mosaicHome: options.mosaicHome,
+    agentEnvDir: options.agentEnvDir,
+    generatedPath,
+    localPath,
+    legacyPath,
+    generated,
+    local,
+    ...(legacy === undefined ? {} : { legacy }),
+    ...(quarantinePath === undefined ? {} : { quarantinePath }),
+    diagnostics: legacyDisposition.diagnostics,
+  };
+}
+
+/** Applies a previously prepared deterministic projection. */
+export async function applyPreparedAgentEnvironmentProjection(
+  prepared: PreparedAgentEnvironmentProjection,
+): Promise<AgentEnvironmentProjectionResult> {
+  await ensurePrivateProjectionDirectory(prepared.mosaicHome, prepared.agentEnvDir);
+  await writePrivateAtomically(prepared.generatedPath, prepared.generated);
+  if (prepared.local !== '') await writePrivateAtomically(prepared.localPath, prepared.local);
+  if (prepared.quarantinePath !== undefined && prepared.legacy !== undefined) {
+    await writePrivateAtomically(prepared.quarantinePath, prepared.legacy);
+  }
+  if (prepared.legacy !== undefined) await unlink(prepared.legacyPath);
+
+  return {
+    generatedPath: prepared.generatedPath,
+    localPath: prepared.localPath,
+    ...(prepared.quarantinePath === undefined ? {} : { quarantinePath: prepared.quarantinePath }),
+    diagnostics: prepared.diagnostics,
+  };
+}
+
+/** Writes deterministic projection files and explicitly removes legacy `.env` authority. */
+export async function writeAgentEnvironmentProjection(
+  options: AgentEnvironmentProjectionOptions,
+): Promise<AgentEnvironmentProjectionResult> {
+  return applyPreparedAgentEnvironmentProjection(await prepareAgentEnvironmentProjection(options));
+}
+
+/** Creates the canonical managed roster path with private fresh-chain permissions. */
+export async function writeManagedFleetRoster(
+  mosaicHome: string,
+  rosterPath: string,
+  content: string,
+): Promise<void> {
+  const fleetDir = join(mosaicHome, 'fleet');
+  const expectedRosterPath = join(fleetDir, 'roster.yaml');
+  if (resolve(rosterPath) !== resolve(expectedRosterPath)) {
+    throw new AgentEnvBoundaryError('unsafe-file', '(roster)', rosterPath);
+  }
+  await ensureManagedDirectory(mosaicHome, false);
+  await ensureManagedDirectory(fleetDir, false);
+  await writePrivateAtomically(rosterPath, content);
+}
+
+/** Ensures the private install-derived identity used to own a named tmux server. */
+export async function ensureFleetHolderIdentity(mosaicHome: string): Promise<string> {
+  const fleetDir = join(mosaicHome, 'fleet');
+  const runDir = join(fleetDir, 'run');
+  const identityPath = join(runDir, 'holder-owner');
+  await ensureManagedDirectory(mosaicHome, false);
+  await ensureManagedDirectory(fleetDir, false);
+  await ensureManagedDirectory(runDir, true);
+  const existing = await readOptionalPrivateFile(identityPath);
+  if (existing !== undefined) {
+    const identity = existing.trim();
+    if (!/^[a-f0-9-]{36}$/.test(identity)) {
+      throw new AgentEnvBoundaryError('unsafe-owner-identity', '(holder-owner)', existing);
+    }
+    return identity;
+  }
+  const identity = randomUUID();
+  await writePrivateAtomically(identityPath, `${identity}\n`);
+  return identity;
+}
+
+function normalizeGeneratedValues(
+  values: Readonly<Record<string, string>>,
+): Readonly<Record<string, string>> {
+  const normalized: Record<string, string> = {};
+  for (const key of GENERATED_AGENT_ENV_KEYS) {
+    const value = values[key];
+    if (value === undefined) throw new AgentEnvBoundaryError('missing-key', key, '');
+    normalized[key] = value;
+  }
+  for (const [key, value] of Object.entries(values)) {
+    if (!GENERATED_KEY_SET.has(key)) throw new AgentEnvBoundaryError('unknown-key', key, value);
+  }
+  assertGeneratedValues(normalized);
+  return Object.freeze(normalized);
+}
+
+function renderLocalAgentEnvironment(values: Readonly<Record<string, string>>): string {
+  if (Object.keys(values).length === 0) return '';
+  const parsed = parseAgentEnvironment(
+    Object.entries(values)
+      .sort(([left], [right]): number => left.localeCompare(right))
+      .map(([key, value]): string => `${key}=${value}`)
+      .join('\n'),
+    'local',
+  );
+  return `${Object.entries(parsed)
+    .sort(([left], [right]): number => left.localeCompare(right))
+    .map(([key, value]): string => `${key}=${value}`)
+    .join('\n')}\n`;
+}
+
+function assertGeneratedValues(values: Readonly<Record<string, string>>): void {
+  for (const key of GENERATED_AGENT_ENV_KEYS) {
+    const value = values[key];
+    if (value === undefined) throw new AgentEnvBoundaryError('missing-key', key, '');
+  }
+  const name = requiredGeneratedValue(values, 'MOSAIC_AGENT_NAME');
+  const className = requiredGeneratedValue(values, 'MOSAIC_AGENT_CLASS');
+  const runtime = requiredGeneratedValue(values, 'MOSAIC_AGENT_RUNTIME');
+  const model = requiredGeneratedValue(values, 'MOSAIC_AGENT_MODEL');
+  const reasoning = requiredGeneratedValue(values, 'MOSAIC_AGENT_REASONING');
+  const toolPolicy = requiredGeneratedValue(values, 'MOSAIC_AGENT_TOOL_POLICY');
+  const workingDirectory = requiredGeneratedValue(values, 'MOSAIC_AGENT_WORKDIR');
+  const socket = requiredGeneratedValue(values, 'MOSAIC_TMUX_SOCKET');
+
+  if (!AGENT_NAME.test(name))
+    throw new AgentEnvBoundaryError('unsafe-agent-name', 'MOSAIC_AGENT_NAME', name);
+  if (!POLICY_NAME.test(className)) {
+    throw new AgentEnvBoundaryError('unsafe-class', 'MOSAIC_AGENT_CLASS', className);
+  }
+  if (!SUPPORTED_RUNTIMES.has(runtime)) {
+    throw new AgentEnvBoundaryError('unsupported-runtime', 'MOSAIC_AGENT_RUNTIME', runtime);
+  }
+  if (!MODEL.test(model))
+    throw new AgentEnvBoundaryError('unsafe-model', 'MOSAIC_AGENT_MODEL', model);
+  if (!REASONING.has(reasoning)) {
+    throw new AgentEnvBoundaryError('unsupported-reasoning', 'MOSAIC_AGENT_REASONING', reasoning);
+  }
+  if (toolPolicy !== '' && !POLICY_NAME.test(toolPolicy)) {
+    throw new AgentEnvBoundaryError('unsafe-tool-policy', 'MOSAIC_AGENT_TOOL_POLICY', toolPolicy);
+  }
+  if (!isSafeAbsolutePath(workingDirectory)) {
+    throw new AgentEnvBoundaryError('unsafe-path', 'MOSAIC_AGENT_WORKDIR', workingDirectory);
+  }
+  if (!TMUX_SOCKET.test(socket)) {
+    throw new AgentEnvBoundaryError('unsafe-socket', 'MOSAIC_TMUX_SOCKET', socket);
+  }
+}
+
+function requiredGeneratedValue(values: Readonly<Record<string, string>>, key: string): string {
+  const value = values[key];
+  if (value === undefined) throw new AgentEnvBoundaryError('missing-key', key, '');
+  return value;
+}
+
+function assertLocalValues(values: Readonly<Record<string, string>>): void {
+  for (const [key, value] of Object.entries(values)) {
+    if (key === 'MOSAIC_HEARTBEAT_INTERVAL') {
+      if (!/^[1-9][0-9]*$/.test(value)) {
+        throw new AgentEnvBoundaryError('invalid-interval', key, value);
+      }
+      continue;
+    }
+    if (!isSafeAbsolutePath(value)) throw new AgentEnvBoundaryError('unsafe-path', key, value);
+  }
+}
+
+function isSafeAbsolutePath(value: string): boolean {
+  return (
+    value.startsWith('/') && !value.split('/').includes('..') && !/[\s"'`$\\;&|<>(){}]/.test(value)
+  );
+}
+
+function containsShellSyntax(value: string): boolean {
+  return /["'`$\\;&|<>(){}]/.test(value);
+}
+
+interface LegacyDisposition {
+  readonly localValues: Readonly<Record<string, string>>;
+  readonly diagnostics: readonly AgentEnvironmentDiagnostic[];
+}
+
+function emptyLegacyDisposition(): LegacyDisposition {
+  return { localValues: {}, diagnostics: [] };
+}
+
+function classifyLegacyEnvironment(source: string): LegacyDisposition {
+  const localValues: Record<string, string> = {};
+  const diagnostics: AgentEnvironmentDiagnostic[] = [];
+  const seen = new Set<string>();
+
+  for (const line of source.split('\n')) {
+    if (line === '') continue;
+    const match = /^([A-Z][A-Z0-9_]*)=(.*)$/.exec(line);
+    if (!match || match[1] === undefined || match[2] === undefined) {
+      diagnostics.push(diagnostic('malformed-line', '(malformed)', line));
+      continue;
+    }
+    const [, key, value] = match;
+    if (seen.has(key)) {
+      diagnostics.push(diagnostic('duplicate-key', key, value));
+      continue;
+    }
+    seen.add(key);
+    if (GENERATED_KEY_SET.has(key)) continue;
+    try {
+      parseAgentEnvironment(`${key}=${value}\n`, 'local');
+      localValues[key] = value;
+    } catch (error: unknown) {
+      if (error instanceof AgentEnvBoundaryError) diagnostics.push(error.diagnostic);
+      else throw error;
+    }
+  }
+
+  return { localValues: Object.freeze(localValues), diagnostics: Object.freeze(diagnostics) };
+}
+
+function diagnostic(code: string, key: string, value: string): AgentEnvironmentDiagnostic {
+  return { code, key, sha256: hashValue(value) };
+}
+
+function hashValue(value: string): string {
+  return createHash('sha256').update(value).digest('hex');
+}
+
+async function readOptionalPrivateFile(path: string): Promise<string | undefined> {
+  try {
+    await assertPrivateRegularFile(path);
+    return await readFile(path, 'utf8');
+  } catch (error: unknown) {
+    if (isMissingFile(error)) return undefined;
+    throw error;
+  }
+}
+
+function isMissingFile(error: unknown): boolean {
+  return typeof error === 'object' && error !== null && 'code' in error && error.code === 'ENOENT';
+}
+
+async function validatePrivateProjectionDirectory(
+  mosaicHome: string,
+  agentEnvDir: string,
+): Promise<void> {
+  const fleetDir = join(mosaicHome, 'fleet');
+  const expectedAgentEnvDir = join(fleetDir, 'agents');
+  if (resolve(agentEnvDir) !== resolve(expectedAgentEnvDir)) {
+    throw new AgentEnvBoundaryError('unsafe-directory', '(directory)', agentEnvDir);
+  }
+  await assertManagedDirectoryIfPresent(mosaicHome, false);
+  await assertManagedDirectoryIfPresent(fleetDir, false);
+  await assertManagedDirectoryIfPresent(agentEnvDir, true);
+}
+
+async function ensurePrivateProjectionDirectory(
+  mosaicHome: string,
+  agentEnvDir: string,
+): Promise<void> {
+  await validatePrivateProjectionDirectory(mosaicHome, agentEnvDir);
+  const fleetDir = join(mosaicHome, 'fleet');
+  await ensureManagedDirectory(mosaicHome, false);
+  await ensureManagedDirectory(fleetDir, false);
+  await ensureManagedDirectory(agentEnvDir, true);
+}
+
+async function ensureManagedDirectory(path: string, privateDirectory: boolean): Promise<void> {
+  let created = false;
+  try {
+    await lstat(path);
+  } catch (error: unknown) {
+    if (!isMissingFile(error)) throw error;
+    try {
+      await mkdir(path, { recursive: true, mode: 0o700 });
+      created = true;
+    } catch (mkdirError: unknown) {
+      if (!isAlreadyExists(mkdirError)) throw mkdirError;
+    }
+  }
+
+  await assertManagedDirectory(path, privateDirectory);
+  if (created) {
+    await chmod(path, 0o700);
+    await assertManagedDirectory(path, privateDirectory);
+  }
+}
+
+function isAlreadyExists(error: unknown): boolean {
+  return typeof error === 'object' && error !== null && 'code' in error && error.code === 'EEXIST';
+}
+
+async function assertManagedDirectoryIfPresent(
+  path: string,
+  privateDirectory: boolean,
+): Promise<void> {
+  try {
+    await assertManagedDirectory(path, privateDirectory);
+  } catch (error: unknown) {
+    if (isMissingFile(error)) return;
+    throw error;
+  }
+}
+
+async function assertManagedDirectory(path: string, privateDirectory: boolean): Promise<void> {
+  const metadata = await lstat(path);
+  if (!metadata.isDirectory()) {
+    throw new AgentEnvBoundaryError('unsafe-directory', '(directory)', path);
+  }
+  if ((metadata.mode & 0o022) !== 0 || (privateDirectory && (metadata.mode & 0o077) !== 0)) {
+    throw new AgentEnvBoundaryError('unsafe-permissions', '(directory)', path);
+  }
+}
+
+async function assertPrivateRegularFileIfPresent(path: string): Promise<void> {
+  try {
+    await assertPrivateRegularFile(path);
+  } catch (error: unknown) {
+    if (isMissingFile(error)) return;
+    throw error;
+  }
+}
+
+async function assertPrivateRegularFile(path: string): Promise<void> {
+  const metadata = await lstat(path);
+  if (!metadata.isFile()) throw new AgentEnvBoundaryError('unsafe-file', '(file)', path);
+  if ((metadata.mode & 0o077) !== 0) {
+    throw new AgentEnvBoundaryError('unsafe-permissions', '(file)', path);
+  }
+}
+
+async function writePrivateAtomically(path: string, content: string): Promise<void> {
+  try {
+    await assertPrivateRegularFile(path);
+  } catch (error: unknown) {
+    if (!isMissingFile(error)) throw error;
+  }
+  const temporaryPath = join(dirname(path), `.${randomUUID()}.tmp`);
+  await writeFile(temporaryPath, content, { encoding: 'utf8', mode: 0o600, flag: 'wx' });
+  await rename(temporaryPath, path);
+}

packages/mosaic/src/fleet/persona-contract.spec.ts

@@ -77,12 +77,25 @@ describe('readPersonaContractBlock — launch-time persona injection (A3b)', ()
   });
 
   it('injects an override-only (user-added) persona with no baseline at all', () => {
-    seedOverride(home, 'reviewer', '# Reviewer\n\n(`class: reviewer`)\n\nCUSTOM-ROLE.\n');
+    seedOverride(home, 'mascot', '# Mascot\n\n(`class: mascot`)\n\nCUSTOM-ROLE.\n');
-    const block = readPersonaContractBlock(home, 'reviewer');
+    const block = readPersonaContractBlock(home, 'mascot');
-    expect(block).toContain('# Persona Contract (reviewer)');
+    expect(block).toContain('# Persona Contract (mascot)');
     expect(block).toContain('CUSTOM-ROLE');
   });
 
+  it('canonicalizes an approved alias before launch-time override lookup', () => {
+    seedBaseline(home, 'code', '# Code\n\n(`class: code`)\n\nCANONICAL-CODE.\n');
+    seedOverride(
+      home,
+      'implementer',
+      '# Legacy implementer\n\n(`class: implementer`)\n\nLEGACY-OVERRIDE.\n',
+    );
+    const block = readPersonaContractBlock(home, 'implementer');
+    expect(block).toContain('# Persona Contract (code)');
+    expect(block).toContain('CANONICAL-CODE');
+    expect(block).not.toContain('LEGACY-OVERRIDE');
+  });
+
   it('no-ops (empty string) when the class is undefined', () => {
     seedBaseline(home, 'coder', BASELINE_CODER);
     expect(readPersonaContractBlock(home, undefined)).toBe('');

packages/mosaic/src/fleet/roster-v2.spec.ts

@@ -1,11 +1,14 @@
-import { readFile } from 'node:fs/promises';
+import { mkdir, mkdtemp, readFile, rm, writeFile } from 'node:fs/promises';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
 import { fileURLToPath } from 'node:url';
-import { describe, expect, it } from 'vitest';
+import { afterEach, describe, expect, it } from 'vitest';
 import {
   ROSTER_V2_JSON_SCHEMA,
   RosterV2ValidationError,
   parseRosterV2,
   renderRosterV2Yaml,
+  validateRosterV2Semantics,
 } from './roster-v2.js';
 
 const validRoster = `
@@ -40,6 +43,127 @@ agents:
       yolo: true
 `;
 
+let semanticTmp: string | undefined;
+
+afterEach(async (): Promise<void> => {
+  if (semanticTmp) await rm(semanticTmp, { recursive: true, force: true });
+  semanticTmp = undefined;
+});
+
+async function semanticDirs(): Promise<{ rolesDir: string; overrideDir: string }> {
+  semanticTmp = await mkdtemp(join(tmpdir(), 'roster-v2-semantics-'));
+  const rolesDir = join(semanticTmp, 'roles');
+  const overrideDir = join(semanticTmp, 'roles.local');
+  await mkdir(rolesDir, { recursive: true });
+  await mkdir(overrideDir, { recursive: true });
+  for (const klass of [
+    'code',
+    'review',
+    'interaction',
+    'orchestrator',
+    'merge-gate',
+    'validator',
+    'team-leader',
+  ]) {
+    await writeFile(join(rolesDir, `${klass}.md`), `# ${klass}\n\n(\`class: ${klass}\`)\n`, 'utf8');
+  }
+  return { rolesDir, overrideDir };
+}
+
+function rosterWithClass(klass: string, toolPolicy = klass): string {
+  return validRoster
+    .replace('class: code', `class: ${klass}`)
+    .replace('tool_policy: code', `tool_policy: ${toolPolicy}`);
+}
+
+describe('roster v2 semantic validation', (): void => {
+  it.each([
+    ['implementer', 'code'],
+    ['reviewer', 'review'],
+    ['operator-interaction', 'interaction'],
+  ])(
+    'canonicalizes requested alias %s while retaining requested and canonical class',
+    async (requested: string, canonical: string) => {
+      const dirs = await semanticDirs();
+      const roster = parseRosterV2(rosterWithClass(requested, requested), 'yaml');
+      const validated = await validateRosterV2Semantics(roster, dirs);
+      expect(validated.agents[0]).toMatchObject({
+        requestedClass: requested,
+        canonicalClass: canonical,
+        canonicalToolPolicy: canonical,
+      });
+    },
+  );
+
+  it.each(['worker', 'analyst', 'canary'])(
+    'rejects %s when no genuine custom role exists',
+    async (klass: string) => {
+      const dirs = await semanticDirs();
+      await expect(
+        validateRosterV2Semantics(parseRosterV2(rosterWithClass(klass), 'yaml'), dirs),
+      ).rejects.toThrow(/unresolved|readable persona/i);
+    },
+  );
+
+  it('accepts a genuine custom roles.local class without protected authority', async () => {
+    const dirs = await semanticDirs();
+    await writeFile(join(dirs.overrideDir, 'worker.md'), '# worker\n\n(`class: worker`)\n', 'utf8');
+    const validated = await validateRosterV2Semantics(
+      parseRosterV2(rosterWithClass('worker'), 'yaml'),
+      dirs,
+    );
+    expect(validated.agents[0]?.authority).toMatchObject({
+      mayMerge: false,
+      mayOrchestrate: false,
+    });
+  });
+
+  it('rejects a LIBRARY-only class with no readable resolved persona', async () => {
+    const dirs = await semanticDirs();
+    await writeFile(
+      join(dirs.rolesDir, 'LIBRARY.md'),
+      '| Persona | Purpose |\n| --- | --- |\n| phantom | Missing |\n',
+      'utf8',
+    );
+    await expect(
+      validateRosterV2Semantics(parseRosterV2(rosterWithClass('phantom'), 'yaml'), dirs),
+    ).rejects.toThrow(/readable persona/i);
+  });
+
+  it('rejects an unreadable resolved persona', async () => {
+    const dirs = await semanticDirs();
+    await mkdir(join(dirs.overrideDir, 'worker.md'));
+    await expect(
+      validateRosterV2Semantics(parseRosterV2(rosterWithClass('worker'), 'yaml'), dirs),
+    ).rejects.toThrow(/readable persona/i);
+  });
+
+  it.each([
+    ['merge-gate', 'code'],
+    ['validator', 'merge-gate'],
+    ['orchestrator', 'interaction'],
+    ['team-leader', 'orchestrator'],
+    ['interaction', 'orchestrator'],
+    ['code', 'merge-gate'],
+    ['worker', 'validator'],
+  ])(
+    'denies protected class/tool-policy mismatch %s with %s',
+    async (klass: string, toolPolicy: string) => {
+      const dirs = await semanticDirs();
+      if (klass === 'worker') {
+        await writeFile(
+          join(dirs.overrideDir, 'worker.md'),
+          '# worker\n\n(`class: worker`)\n',
+          'utf8',
+        );
+      }
+      await expect(
+        validateRosterV2Semantics(parseRosterV2(rosterWithClass(klass, toolPolicy), 'yaml'), dirs),
+      ).rejects.toThrow(/tool policy.*must match|mismatch/i);
+    },
+  );
+});
+
 describe('roster v2 structural compiler', (): void => {
   it('parses YAML into a normalized typed model and renders canonical YAML', (): void => {
     const roster = parseRosterV2(validRoster, 'yaml');

packages/mosaic/src/fleet/roster-v2.ts

@@ -1,4 +1,15 @@
 import YAML from 'yaml';
+import {
+  authorityForCanonicalClass,
+  canonicalizeRoleClass,
+  defaultOverrideDir,
+  defaultRolesDir,
+  extractClassesFromDir,
+  resolvePersonaFrom,
+  type PersonaDirs,
+  type PersonaResolution,
+  type RoleAuthority,
+} from '../commands/fleet-personas.js';
 
 export const ROSTER_V2_SUPPORTED_RUNTIMES = ['claude', 'codex', 'opencode', 'pi'] as const;
 export const ROSTER_V2_REASONING_LEVELS = ['low', 'medium', 'high'] as const;
@@ -58,6 +69,80 @@ export interface FleetRosterV2 {
   readonly agents: readonly FleetRosterV2Agent[];
 }
 
+export interface SemanticallyValidatedRosterV2Agent extends FleetRosterV2Agent {
+  readonly requestedClass: string;
+  readonly canonicalClass: string;
+  readonly canonicalToolPolicy: string;
+  readonly persona: PersonaResolution;
+  readonly authority: RoleAuthority;
+}
+
+export interface SemanticallyValidatedRosterV2 extends Omit<FleetRosterV2, 'agents'> {
+  readonly agents: readonly SemanticallyValidatedRosterV2Agent[];
+}
+
+const PROTECTED_TOOL_POLICY_CLASSES = new Set([
+  'merge-gate',
+  'validator',
+  'orchestrator',
+  'team-leader',
+  'interaction',
+]);
+
+/**
+ * Validate filesystem-backed roster semantics after synchronous structural parsing.
+ * Directory scans are batched once and every class must resolve to readable content.
+ */
+export async function validateRosterV2Semantics(
+  roster: FleetRosterV2,
+  opts: PersonaDirs = {},
+): Promise<SemanticallyValidatedRosterV2> {
+  const rolesDir = opts.rolesDir ?? defaultRolesDir(opts.mosaicHome);
+  const overrideDir = opts.overrideDir ?? defaultOverrideDir(opts.mosaicHome);
+  const [base, over] = await Promise.all([
+    extractClassesFromDir(rolesDir),
+    extractClassesFromDir(overrideDir),
+  ]);
+
+  const agents: SemanticallyValidatedRosterV2Agent[] = [];
+  for (const agent of roster.agents) {
+    const requestedClass = agent.className;
+    const { canonicalClass } = canonicalizeRoleClass(requestedClass);
+    const canonicalToolPolicy = canonicalizeRoleClass(agent.toolPolicy).canonicalClass;
+    const persona = await resolvePersonaFrom(requestedClass, {
+      rolesDir,
+      overrideDir,
+      base,
+      over,
+    });
+    if (!persona || persona.content.trim() === '') {
+      throw new RosterV2ValidationError(
+        `Roster v2 agent "${agent.name}" class "${requestedClass}" does not resolve to a readable persona.`,
+      );
+    }
+    if (
+      (PROTECTED_TOOL_POLICY_CLASSES.has(canonicalClass) ||
+        PROTECTED_TOOL_POLICY_CLASSES.has(canonicalToolPolicy)) &&
+      canonicalToolPolicy !== canonicalClass
+    ) {
+      throw new RosterV2ValidationError(
+        `Roster v2 agent "${agent.name}" protected class "${canonicalClass}" tool policy must match its canonical class; received "${agent.toolPolicy}".`,
+      );
+    }
+    agents.push(
+      Object.freeze({
+        ...agent,
+        requestedClass,
+        canonicalClass,
+        canonicalToolPolicy,
+        persona,
+        authority: authorityForCanonicalClass(canonicalClass),
+      }),
+    );
+  }
+  return Object.freeze({ ...roster, agents: Object.freeze(agents) });
+}
+
 export class RosterV2ValidationError extends Error {
   constructor(message: string) {
     super(message);