feat(fleet): orchestrator-mutable fleet — fleet add/remove (F5/R9)

- Pure helpers: addAgentToRoster, removeAgentFromRoster, serializeRosterToYaml
- fleet add <name> --runtime --class [--model] [--working-dir] [--no-start]
- fleet remove <name> [--keep-files]
- Guard: refuse to remove the sole orchestrator (R5)
- Unit tests for all pure helpers and command wiring via injected runner

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RMoEx7hfdFGjUiCHuN1RRi

docs/TASKS.md

@@ -45,9 +45,3 @@ Active workstream is **W1 — Federation v1**. Workers should:
 - Status: PR open, awaiting maintainer merge ratification (fleet-governing change).
 - Cut always-injected contract AGENTS+TOOLS+RUNTIME 8,827→4,122 tok (−53%); all 12 hard gates intact.
 - Validation: deterministic gate-checklist PASS; headless A/B thin 7/9 vs monolith 5/9. Detail: scratchpads/contract-thin-core.md.
-
-## P5 — Overlay composer + cross-harness (#604) — feat/p5-overlay-composer
-
-- Status: in progress. R7 (compose-contract) + R8 (cross-harness) + R9 (composer test).
-- `composeContract({harness, mosaicHome})` pure fn + `.local` overlay deltas-by-value; `mosaic compose-contract <harness>` command; AGENTS bare-launch nudge; composer spec (per-tier anchor + Tier-3 byte-equality). Detail: scratchpads/p5-overlay-composer.md.
-- Defer to P6: CONTRIBUTING.md + compliance matrix; line-count CI ceiling; aiguide; alpha tag.

docs/fleet/PRD-fleet-suite.md

@@ -1,109 +0,0 @@
-# PRD — Mosaic Fleet Suite (init, configure, operate)
-
-> **Workstream:** W-FLEET (Fleet) under mission `mvp-20260312` · **Phase:** 3→4 productization
-> **North star:** [docs/fleet/north-star.md](./north-star.md) · prior: Phase-2 observability (#579), durable launch (#581), real-agent enablement (#583/#584/#586), releases 0.0.35–0.0.37
-> **Lead:** Jarvis @ `w-jarvis`. **Collaborator:** coder agent @ `dragon-lin` (jwoltje@10.1.10.37:coder0-0).
-> Owner of this file: Fleet workstream lead. Does not modify MVP single-writer control-plane files.
-
-## Mission
-
-Turn the proven fleet primitives into a **user-installable, AI-free-configurable fleet product**:
-a user runs `mosaic fleet init`, answers a few questions (general / coding / research / hybrid),
-gets a recommended set of agents plus one always-on orchestrator wired for chat-ops, and can
-operate, mutate, re-create, and observe the fleet — over tmux today and Matrix tomorrow — from
-CLI/TUI and (designed-for) the webUI.
-
-**Immediate tangible goal:** the **"Mos"** orchestrator agent running on `w-jarvis`, reachable
-in **Discord channel `1517622518662434996`** (server `1112631390438166618`). Once the fleet is
-functional, we use the fleet itself to continue the work.
-
-## Requirements
-
-### A. Configure-without-AI CLI
-
-| ID  | Requirement                                                                                                   |
-| --- | ------------------------------------------------------------------------------------------------------------- |
-| R1  | `mosaic fleet` command set is functional end-to-end (init/install/start/stop/status/ps/verify + agent verbs). |
-| R2  | `mosaic fleet init` is an interactive, **AI-free** CLI wizard.                                                |
-| R3  | Init asks the **configuration type**: `general`, `coding`, `research`, `hybrid`, … (extensible).              |
-| R4  | Based on the answer, the fleet is populated with a **recommended set of agents** (a preset).                  |
-| R5  | **Exactly one main orchestrator agent** is always configured, regardless of type.                             |
-| R10 | A set of **recommended configurations (presets)** ships for easy duplication.                                 |
-| R8  | User can **re-create** the fleet when config needs change (idempotent re-init / reconfigure).                 |
-| R17 | Fleet controls are **simple and intuitive**.                                                                  |
-
-### B. Comms & orchestrator chat-ops
-
-| ID  | Requirement                                                                                                                       |
-| --- | --------------------------------------------------------------------------------------------------------------------------------- |
-| R6  | Init can wire the orchestrator to a chat connector — **Telegram / Discord / Matrix / Slack** — for command + comms.               |
-| R7  | Designed with the end-goal of **Matrix comms on a locally-controlled server**.                                                    |
-| R16 | Fleet supports **tmux AND Matrix** comms, **user-configurable** at init or any time. Not all users want Matrix.                   |
-| R19 | **"Mos" orchestrator on Discord** (`chan 1517622518662434996` / `srv 1112631390438166618`) on `w-jarvis` — the first live target. |
-
-### C. Runtime, health, lifecycle
-
-| ID  | Requirement                                                                        |
-| --- | ---------------------------------------------------------------------------------- |
-| R9  | Fleet is **mutable by the orchestrator agent** — add/remove agents per need.       |
-| R13 | Fleet **gracefully handles Pi + Claude harness updates** — keep harnesses current. |
-| R14 | The **Pi harness is customized** for proper tool usage, etc.                       |
-| R15 | **Agent heartbeat** properly configured for **Claude AND GPT/Pi** agents.          |
-
-### D. Surfaces, testing, docs
-
-| ID  | Requirement                                                                         |
-| --- | ----------------------------------------------------------------------------------- |
-| R18 | Fleet built so the **webUI can view / monitor / terminate / butt-in** on a session. |
-| R11 | Installed and **tested on both `w-jarvis` and `dragon-lin`**.                       |
-| R12 | **Documentation**: how to install, configure, and use the fleet.                    |
-
-## Architecture / approach
-
-- **Config model:** `roster.yaml` is the source of truth (already exists). Add **presets** (`general`/`coding`/`research`/`hybrid`) as shipped example rosters; `init` selects a preset, always injects the orchestrator, and writes the roster. Re-init = regenerate roster (preserve user/site overrides — mirrors install env-merge from #567).
-- **Orchestrator agent:** always present; carries the chat connector config (connector type + target IDs) so it can be commanded over chat. tmux is the substrate; the connector bridges chat ↔ the orchestrator session.
-- **Comms layers (R16):** (1) **tmux** inter-agent (`agent-send`, proven) — default, always available. (2) **chat connector** for human↔orchestrator (Discord now; Matrix the strategic target). (3) **Matrix** as the locally-controlled cross-agent bus (future). Connector is pluggable + reconfigurable.
-- **Heartbeat (R15):** runtime-agnostic launcher sidecar already covers pi/claude/codex (#584). Refine per-runtime (native HB) with the **custom Pi harness** (R14) + a Claude path.
-- **Updates (R13):** `mosaic update` (CLI) + a fleet-aware harness-update step that refreshes pi/claude/codex and re-launches agents safely (drain → update → relaunch via the durable launcher).
-- **webUI (R18):** the fleet exposes machine-readable state (`fleet ps --json` already carries tenant/host/heartbeat/managed) + control verbs (start/stop/watch/send); webUI consumes these (control plane rides federation per north star). Ensure a stable JSON contract + a terminate/attach(butt-in) path.
-
-## Phases (incremental, each shippable)
-
-| Phase                             | Deliverable                                                                                                                         | Notes                                 |
-| --------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------- |
-| **F1 Presets + init wizard**      | preset rosters (general/coding/research/hybrid) + always-orchestrator + AI-free `fleet init` selecting a preset; re-init idempotent | R1–R5, R8, R10, R17                   |
-| **F2 Connector + Mos-on-Discord** | orchestrator chat-connector config (Discord first) + **Mos live on Discord `1517…`/`1112…`** on w-jarvis                            | R6, R19, partial R16                  |
-| **F3 Heartbeat + harness**        | HB confirmed for claude + pi/gpt; **custom Pi harness** (tool usage, native HB, model self-report); graceful harness updates        | R13, R14, R15                         |
-| **F4 Matrix + comms toggle**      | Matrix connector (local server) + user toggle tmux/Matrix at init/anytime                                                           | R7, R16                               |
-| **F5 Orchestrator-mutable fleet** | orchestrator can add/remove agents at runtime                                                                                       | R9                                    |
-| **F6 webUI hooks**                | stable JSON contract + terminate/attach surface for webUI view/monitor/terminate/butt-in                                            | R18                                   |
-| **F7 Test + docs**                | install+test on w-jarvis AND dragon-lin; user docs (install/configure/use)                                                          | R11, R12 (runs alongside every phase) |
-
-## Work division (proposed — confirm with dragon-lin)
-
-- **Jarvis @ w-jarvis (Lead):** F1 presets+wizard, F2 connector+Mos-on-Discord, F5 mutability, F6 webUI hooks; merge authority + dual-engine reviews; co-testing on w-jarvis.
-- **coder @ dragon-lin:** F3 custom Pi harness + harness-update flow (pi/codex-savvy); plus its in-flight constitution P4–P6 (P4 installer rework underpins `fleet init`/updates — coordinate the install path). Co-testing on dragon-lin (R11).
-- **Shared:** F4 Matrix (whoever has bandwidth); F7 testing/docs continuous.
-
-## Immediate target: Mos on Discord (F2 first slice)
-
-The discord plugin is available (`~/.claude.json`). Path: configure the **orchestrator** as a durable
-fleet session running Claude Code with the discord plugin bridged to channel `1517622518662434996`
-(server `1112631390438166618`) on w-jarvis, with the existing Discord Bridge Protocol (ack within
-~3s, reply via `mcp__discord__reply`, no `AskUserQuestion`). Heartbeat via the launcher sidecar.
-
-## Success criteria
-
-- A non-AI user can `mosaic fleet init`, pick a type, and get a working fleet + orchestrator.
-- **Mos answers in Discord `1517…`** on w-jarvis.
-- Fleet runs + is observable (`fleet ps`) on **both** w-jarvis and dragon-lin.
-- Harness updates handled gracefully; HB healthy for claude + pi/gpt agents.
-- Docs let a new operator install/configure/use the fleet.
-- Re-init + orchestrator mutation work.
-
-## Assumptions (veto-able)
-
-- `ASSUMPTION:` presets ship as example rosters under the framework (`fleet/examples/*.yaml`), selected by `init`.
-- `ASSUMPTION:` chat connectors are pluggable; Discord first (target exists), Matrix is the strategic default later.
-- `ASSUMPTION:` "Mos" = a Claude Code orchestrator session with the discord plugin (reuses the documented Discord Bridge Protocol).
-- `ASSUMPTION:` per north star, runtimes default to Codex/pi-on-Codex for workers; the orchestrator "Mos" runs Claude Code (in Claude Code, which is allowed).

docs/scratchpads/p5-overlay-composer.md

@@ -1,43 +0,0 @@
-# P5 — Overlay composer + cross-harness (compose-contract)
-
-- **Issue:** #604 · **Branch:** `feat/p5-overlay-composer` · **Lineage:** #542 → constitution alpha
-- **Requirements:** R7 (compose-contract) + R8 (cross-harness) + R9 (composer test)
-- **Design of record:** `docs/design/framework-constitution/{DESIGN.md §3.2, PRD.md §4}` (on `feat/framework-constitution-alpha`)
-
-## Locked design (sequential-thinking)
-
-Current `launch.ts` assembly (`buildComposedPrompt`) injects by value: mission + PRD + hard-gate +
-CONSTITUTION + AGENTS + USER + TOOLS + runtime. It does **not** inject SOUL or STANDARDS (those are
-read-on-demand per the gutted AGENTS dispatcher), and has no `.local` overlay support.
-
-**Decision (ASSUMPTION — recorded for the PR):** overlays are injected as **deltas by value** under
-labeled sections; base files keep their existing residency.
-
-- `USER.local.md` → appended directly under the `# User Profile` block (USER is injected).
-- `SOUL.local.md` + `STANDARDS.local.md` → a trailing `# Operator Overlays` section (their bases are
-  load-on-demand, so only the small delta is injected — not the full base prose).
-- **Why:** honors DESIGN §3.2 ("model gets one pre-merged blob, no read-merge ritual") while preserving
-  the P3 byte-budget tiering (don't re-inject large SOUL/STANDARDS prose). Precedence order kept: base
-  layers first, operator overlays at recency.
-- Base-only is automatic when a `.local` file is absent (`readOptional`).
-
-## Plan
-
-| #   | Task                                                                                                   | File                                    |
-| --- | ------------------------------------------------------------------------------------------------------ | --------------------------------------- |
-| 1   | Extract `composeContract({harness, mosaicHome})` pure fn; `buildComposedPrompt` delegates              | `src/commands/launch.ts`                |
-| 2   | Overlay logic (USER.local under profile; SOUL/STANDARDS.local in `# Operator Overlays`)                | `src/commands/launch.ts`                |
-| 3   | `mosaic compose-contract <harness>` command → prints blob to stdout                                    | `src/commands/launch.ts`                |
-| 4   | Bare-launch overlay nudge in self-load fallback                                                        | `framework/defaults/AGENTS.md`          |
-| 5   | `compose-contract.spec.ts`: per-tier anchor, Tier-3 byte-equality, overlay present/absent, per-harness | `src/commands/compose-contract.spec.ts` |
-
-## Deferred to P6
-
-CONTRIBUTING.md + harness×gate compliance matrix; resident line-count CI ceiling; `aiguide` reconcile;
-alpha tag `mosaic-vX.Y.Z-alpha`.
-
-## Status
-
-- [x] Phase scaffold (branch, issue #604, scratchpad, TASKS)
-- [ ] Implementation (tasks 1–5)
-- [ ] prettier + vitest green; PR via wrapper → Lead (rides 0.0.39; 0.0.38 mid-cut)

packages/mosaic/framework/defaults/AGENTS.md

@@ -9,10 +9,7 @@ overwritten on upgrade. (Layer model: `constitution/LAYER-MODEL.md`.)
 1. Your context already includes `CONSTITUTION.md` + `USER.md` + the TOOLS index + the runtime
    contract (injected by `mosaic` launch) — do not re-read those. **If you were launched bare**
    (a harness started without `mosaic`, so the law is NOT in your context), read
-   `~/.config/mosaic/CONSTITUTION.md` now, before your first action. A bare launch also gets
+   `~/.config/mosaic/CONSTITUTION.md` now, before your first action.
-   **base contracts only** — operator overlays (`*.local.md`) are composed by the launcher, so if
-   `SOUL.local.md`/`USER.local.md`/`STANDARDS.local.md` exist, relaunch via `mosaic <harness>` (or run
-   `mosaic doctor`) to pick them up.
 2. Read `SOUL.md` (agent persona — small, once).
 3. Read project-local `AGENTS.md` / `CLAUDE.md` if present (these may only make behavior stricter).
 4. Read guides ONLY as triggered by the table below — pull role-relevant depth on demand, not up front.

packages/mosaic/framework/runtime/pi/mosaic-extension.ts

@@ -9,16 +9,8 @@
  *   4. Memory routing — remind agent to use ~/.config/mosaic/memory/
  */
 
-import type { ExtensionAPI, ExtensionContext } from '@earendil-works/pi-coding-agent';
+import type { ExtensionAPI } from '@mariozechner/pi-coding-agent';
-import { Type } from 'typebox';
+import { existsSync, readFileSync, writeFileSync, unlinkSync, mkdirSync } from 'node:fs';
-import {
-  existsSync,
-  readFileSync,
-  writeFileSync,
-  unlinkSync,
-  mkdirSync,
-  renameSync,
-} from 'node:fs';
 import { join, basename } from 'node:path';
 import { homedir } from 'node:os';
 import { execSync, spawnSync } from 'node:child_process';
@@ -33,57 +25,6 @@ const MOSAIC_HOME = process.env['MOSAIC_HOME'] ?? join(homedir(), '.config', 'mo
 // Helpers
 // ---------------------------------------------------------------------------
 
-// ---------------------------------------------------------------------------
-// Native heartbeat (fleet R14/R15)
-// ---------------------------------------------------------------------------
-// When this agent runs under the Mosaic fleet (MOSAIC_AGENT_NAME set), the
-// extension writes its OWN heartbeat in the same .hb contract `fleet ps` reads
-// (ts/pid/status[/model]) and touches a `.hb.native` precedence marker so the
-// shell sidecar defers. Native HB knows the real turn state (busy/ok), so it is
-// more accurate than the pane-PID-only sidecar fallback.
-const HB_AGENT_NAME = process.env['MOSAIC_AGENT_NAME'] ?? '';
-const HB_RUN_DIR = process.env['MOSAIC_HEARTBEAT_RUN_DIR'] ?? join(MOSAIC_HOME, 'fleet', 'run');
-const HB_INTERVAL_MS = (() => {
-  const s = Number.parseInt(process.env['MOSAIC_HEARTBEAT_INTERVAL'] ?? '', 10);
-  return Number.isFinite(s) && s > 0 ? s * 1000 : 15_000;
-})();
-
-function nativeHbEnabled(): boolean {
-  return HB_AGENT_NAME.length > 0;
-}
-
-function readModelId(ctx: ExtensionContext): string | null {
-  const m = ctx.model as unknown as { id?: string; name?: string } | undefined;
-  return m?.id ?? m?.name ?? null;
-}
-
-function writeNativeHeartbeat(status: 'ok' | 'busy', model: string | null): void {
-  if (!nativeHbEnabled()) return;
-  try {
-    mkdirSync(HB_RUN_DIR, { recursive: true });
-    const hb = join(HB_RUN_DIR, `${HB_AGENT_NAME}.hb`);
-    const lines = [`ts=${nowIso()}`, `pid=${process.pid}`, `status=${status}`];
-    if (model) lines.push(`model=${model}`);
-    const tmp = `${hb}.tmp.${process.pid}`;
-    writeFileSync(tmp, lines.join('\n') + '\n');
-    renameSync(tmp, hb); // atomic replace — fleet ps never reads a partial file
-    // Precedence marker: tells the shell sidecar that native HB is authoritative.
-    writeFileSync(join(HB_RUN_DIR, `${HB_AGENT_NAME}.hb.native`), nowIso() + '\n');
-  } catch {
-    // Best-effort: never let heartbeat I/O disrupt the Pi session.
-  }
-}
-
-function clearNativeMarker(): void {
-  if (!nativeHbEnabled()) return;
-  try {
-    const m = join(HB_RUN_DIR, `${HB_AGENT_NAME}.hb.native`);
-    if (existsSync(m)) unlinkSync(m); // native stopping — let the sidecar take over
-  } catch {
-    /* ignore */
-  }
-}
-
 function safeRead(filePath: string): string | null {
   try {
     return readFileSync(filePath, 'utf-8');
@@ -246,9 +187,6 @@ function buildMissionSummary(cwd: string, mission: ActiveMission): string {
 
 export default function register(pi: ExtensionAPI) {
   let sessionCwd = process.cwd();
-  let hbStatus: 'ok' | 'busy' = 'ok';
-  let hbModel: string | null = null;
-  let hbTimer: ReturnType<typeof setInterval> | null = null;
 
   // ── Session Start ─────────────────────────────────────────────────────
   pi.on('session_start', async (_event, ctx) => {
@@ -269,39 +207,10 @@ export default function register(pi: ExtensionAPI) {
     } else {
       ctx.ui.notify('Mosaic framework loaded', 'info');
     }
-
-    // Native heartbeat: write immediately, then on an interval. Idle = 'ok';
-    // turn_start/turn_end flip the status so `fleet ps` reflects real activity.
-    if (nativeHbEnabled()) {
-      hbModel = readModelId(ctx);
-      writeNativeHeartbeat('ok', hbModel);
-      hbTimer = setInterval(() => writeNativeHeartbeat(hbStatus, hbModel), HB_INTERVAL_MS);
-      if (typeof hbTimer.unref === 'function') hbTimer.unref();
-    }
   });
 
-  // ── Turn lifecycle → accurate busy/ok heartbeat ───────────────────────
+  // ── Session End ───────────────────────────────────────────────────────
-  pi.on('turn_start', async (_event, ctx) => {
+  pi.on('session_end', async (_event, _ctx) => {
-    hbStatus = 'busy';
-    hbModel = readModelId(ctx) ?? hbModel;
-    writeNativeHeartbeat('busy', hbModel);
-  });
-  pi.on('turn_end', async (_event, ctx) => {
-    hbStatus = 'ok';
-    hbModel = readModelId(ctx) ?? hbModel;
-    writeNativeHeartbeat('ok', hbModel);
-  });
-
-  // ── Session Shutdown ──────────────────────────────────────────────────
-  // (The pi API event is 'session_shutdown'; the prior 'session_end' handler
-  // never fired — fixed here so repo hooks + lock cleanup actually run.)
-  pi.on('session_shutdown', async (_event, _ctx) => {
-    if (hbTimer) {
-      clearInterval(hbTimer);
-      hbTimer = null;
-    }
-    clearNativeMarker();
-
     // Run repo session-end hook
     runRepoHook(sessionCwd, 'session-end');
 
@@ -343,32 +252,4 @@ export default function register(pi: ExtensionAPI) {
       }
     },
   });
-
-  // ── Register mosaic_mission_status tool (model-callable) ──────────────
-  // R14 "proper tool usage": give the agent a first-class tool to load its
-  // active Mosaic mission, milestone progress, task counts, and latest
-  // scratchpad — so it self-orients on in-flight work before planning,
-  // instead of shelling out or guessing. Mirrors the /mosaic-status command
-  // but returns the summary as tool output the LLM can read.
-  pi.registerTool({
-    name: 'mosaic_mission_status',
-    label: 'Mosaic Mission Status',
-    description:
-      'Return the active Mosaic mission, milestone progress, task counts, and latest scratchpad for the current project. Returns a note when no mission is active.',
-    promptSnippet: 'Read the active Mosaic mission + task state for the current project',
-    promptGuidelines: [
-      'Use mosaic_mission_status at the start of a session or task to load the active mission, milestone progress, and open tasks before planning work.',
-    ],
-    parameters: Type.Object({}),
-    async execute(_toolCallId, _params, _signal, _onUpdate, _ctx) {
-      const mission = detectMission(sessionCwd);
-      const text = mission
-        ? buildMissionSummary(sessionCwd, mission)
-        : 'No active Mosaic mission in this project.';
-      return {
-        content: [{ type: 'text', text }],
-        details: mission ? { ...mission } : { active: false },
-      };
-    },
-  });
 }

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

@@ -6,7 +6,7 @@ MOSAIC_TMUX_SOCKET=${MOSAIC_TMUX_SOCKET:-mosaic-factory}
 MOSAIC_AGENT_RUNTIME=${MOSAIC_AGENT_RUNTIME:-pi}
 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_RUN_DIR=${MOSAIC_HEARTBEAT_RUN_DIR:-$HOME/.config/mosaic/fleet/run}
 MOSAIC_HEARTBEAT_INTERVAL=${MOSAIC_HEARTBEAT_INTERVAL:-15}
 
 if [ -z "$AGENT_NAME" ]; then
@@ -90,18 +90,11 @@ MOSAIC_RUNTIME_BIN_PREFIX=$(_build_runtime_bin_prefix)
 #
 # 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")
 
 if [ -n "$MOSAIC_RUNTIME_BIN_PREFIX" ]; then
-  PANE_SHELL_SNIPPET="export MOSAIC_AGENT_NAME=${AGENT_NAME_Q}; export PATH=\"${MOSAIC_RUNTIME_BIN_PREFIX}:\${PATH}\"; exec ${MOSAIC_AGENT_COMMAND}"
+  PANE_SHELL_SNIPPET="export PATH=\"${MOSAIC_RUNTIME_BIN_PREFIX}:\${PATH}\"; exec ${MOSAIC_AGENT_COMMAND}"
 else
-  PANE_SHELL_SNIPPET="export MOSAIC_AGENT_NAME=${AGENT_NAME_Q}; exec ${MOSAIC_AGENT_COMMAND}"
+  PANE_SHELL_SNIPPET="exec ${MOSAIC_AGENT_COMMAND}"
 fi
 
 mkdir -p "$MOSAIC_AGENT_WORKDIR"
@@ -136,7 +129,7 @@ _start_heartbeat_sidecar() {
   # references to any variables from this script's environment.
   local sidecar_script
   sidecar_script=$(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.$$"; printf "ts=%%s\npid=%%s\nstatus=ok\n" "$(date +%%Y-%%m-%%dT%%H:%%M:%%S%%z)" "$pid" > "$tmp" && mv "$tmp" "$hb"; sleep "$iv"; done' \
+    'hb=%s; pid=%s; iv=%s; mkdir -p "$(dirname "$hb")"; while kill -0 "$pid" 2>/dev/null; do tmp="$hb.tmp.$$"; printf "ts=%%s\npid=%%s\nstatus=ok\n" "$(date +%%Y-%%m-%%dT%%H:%%M:%%S%%z)" "$pid" > "$tmp" && mv "$tmp" "$hb"; sleep "$iv"; done' \
     "$hb_file" "$pane_pid" "$interval")
 
   # setsid + disown ensures the sidecar survives this script exiting.

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

@@ -32,15 +32,8 @@ 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
+[ "$actual_dir" = "$WORKDIR" ] || fail "agent workdir mismatch: $actual_dir"
-  sleep 0.1
-done
-[ "$actual_dir" = "$WORKDIR" ] || fail "agent workdir mismatch: $actual_dir (expected $WORKDIR)"
 
 # ── Test 2: idempotency (duplicate start prints 'already running') ─────────────
 MOSAIC_TMUX_SOCKET="$SOCKET" \

packages/mosaic/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@mosaicstack/mosaic",
-  "version": "0.0.37",
+  "version": "0.0.36",
   "repository": {
     "type": "git",
     "url": "https://git.mosaicstack.dev/mosaicstack/stack.git",

packages/mosaic/src/commands/compose-contract.spec.ts

@@ -1,118 +0,0 @@
-import { describe, it, expect, beforeEach, afterEach } from 'vitest';
-import { mkdtempSync, mkdirSync, writeFileSync, rmSync, readFileSync } from 'node:fs';
-import { tmpdir } from 'node:os';
-import { join } from 'node:path';
-import { composeContract } from './launch.js';
-
-/**
- * Composer unit test (R7/R8/R9): asserts the launcher-composed runtime contract
- *
- *   - includes the per-tier anchors (CONSTITUTION / AGENTS / USER / runtime),
- *   - keeps the CONSTITUTION block byte-equal to the on-disk file (Tier-3
- *     byte-equality — the bare-launch fallback read must match what is injected),
- *   - merges `*.local.md` operator overlays as deltas-by-value, and omits them
- *     entirely when absent (base-only),
- *   - selects the correct per-harness RUNTIME.md.
- *
- * `composeContract` takes `mosaicHome` as a param, so each test runs against an
- * isolated fixture home. We also chdir to an empty temp cwd so the cwd-relative
- * mission/PRD blocks contribute nothing (deterministic output).
- */
-
-const CONSTITUTION = '# CONSTITUTION\n\nGATE-1: the non-negotiable law.\n';
-const AGENTS = '# Mosaic Agent Dispatcher\n\nLoad order + guide router.\n';
-const USER = '# operator\n\nName: Test Operator\n';
-const TOOLS = '# tools index\n';
-
-function makeHome(): { home: string; root: string } {
-  const root = mkdtempSync(join(tmpdir(), 'mosaic-compose-'));
-  const home = join(root, 'mosaic-home');
-  for (const h of ['claude', 'codex', 'opencode', 'pi']) {
-    mkdirSync(join(home, 'runtime', h), { recursive: true });
-    writeFileSync(join(home, 'runtime', h, 'RUNTIME.md'), `# ${h} runtime contract\n`);
-  }
-  writeFileSync(join(home, 'CONSTITUTION.md'), CONSTITUTION);
-  writeFileSync(join(home, 'AGENTS.md'), AGENTS);
-  writeFileSync(join(home, 'USER.md'), USER);
-  writeFileSync(join(home, 'TOOLS.md'), TOOLS);
-  return { home, root };
-}
-
-describe('composeContract — overlay composer', () => {
-  let fixture: ReturnType<typeof makeHome>;
-  let prevCwd: string;
-  let cwdDir: string;
-
-  beforeEach(() => {
-    fixture = makeHome();
-    prevCwd = process.cwd();
-    cwdDir = mkdtempSync(join(tmpdir(), 'mosaic-cwd-'));
-    process.chdir(cwdDir); // neutralize cwd-relative mission/PRD blocks
-  });
-
-  afterEach(() => {
-    process.chdir(prevCwd);
-    rmSync(fixture.root, { recursive: true, force: true });
-    rmSync(cwdDir, { recursive: true, force: true });
-  });
-
-  it('includes the per-tier anchors and the selected harness runtime', () => {
-    const out = composeContract('claude', fixture.home);
-    expect(out).toContain('GATE-1: the non-negotiable law.'); // L0
-    expect(out).toContain('Mosaic Agent Dispatcher'); // AGENTS
-    expect(out).toContain('# User Profile'); // USER header
-    expect(out).toContain('Name: Test Operator'); // USER body
-    expect(out).toContain('# Runtime-Specific Contract');
-    expect(out).toContain('# claude runtime contract');
-  });
-
-  it('keeps the CONSTITUTION block byte-equal to the on-disk file (Tier-3)', () => {
-    const out = composeContract('pi', fixture.home);
-    const onDisk = readFileSync(join(fixture.home, 'CONSTITUTION.md'), 'utf-8');
-    // The injected L0 must be a byte-equal substring of the composed blob, so a
-    // bare-launch fallback read of CONSTITUTION.md matches what was injected.
-    expect(out.includes(onDisk)).toBe(true);
-  });
-
-  it('is base-only when no *.local overlays exist', () => {
-    const out = composeContract('claude', fixture.home);
-    expect(out).not.toContain('# Operator Overlays');
-    expect(out).not.toContain('Operator Overlay (USER.local.md)');
-    expect(out).not.toContain('Persona Overlay');
-    expect(out).not.toContain('Standards Overlay');
-  });
-
-  it('merges USER.local.md directly under the operator profile', () => {
-    writeFileSync(join(fixture.home, 'USER.local.md'), 'Prefer terse status updates.\n');
-    const out = composeContract('claude', fixture.home);
-    expect(out).toContain('## Operator Overlay (USER.local.md)');
-    expect(out).toContain('Prefer terse status updates.');
-    // Overlay appears AFTER its base profile.
-    expect(out.indexOf('# User Profile')).toBeLessThan(
-      out.indexOf('## Operator Overlay (USER.local.md)'),
-    );
-  });
-
-  it('merges SOUL.local.md + STANDARDS.local.md as deltas in the Operator Overlays block', () => {
-    writeFileSync(join(fixture.home, 'SOUL.local.md'), 'Tone: dry and direct.\n');
-    writeFileSync(join(fixture.home, 'STANDARDS.local.md'), 'Require 90% coverage on auth code.\n');
-    const out = composeContract('claude', fixture.home);
-    expect(out).toContain('# Operator Overlays');
-    expect(out).toContain('## Persona Overlay (SOUL.local.md)');
-    expect(out).toContain('Tone: dry and direct.');
-    expect(out).toContain('## Standards Overlay (STANDARDS.local.md)');
-    expect(out).toContain('Require 90% coverage on auth code.');
-  });
-
-  it('ignores whitespace-only *.local overlays (no empty overlay section)', () => {
-    writeFileSync(join(fixture.home, 'SOUL.local.md'), '   \n\n');
-    const out = composeContract('claude', fixture.home);
-    expect(out).not.toContain('# Operator Overlays');
-  });
-
-  it('selects a different RUNTIME.md per harness', () => {
-    expect(composeContract('codex', fixture.home)).toContain('# codex runtime contract');
-    expect(composeContract('pi', fixture.home)).toContain('# pi runtime contract');
-    expect(composeContract('codex', fixture.home)).not.toContain('# pi runtime contract');
-  });
-});

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

@@ -833,17 +833,6 @@ describe('fleet ps — heartbeat parsing', () => {
     expect(hb.pid).toBe(12345);
     expect(hb.status).toBe('ok');
     expect(hb.ageMs).toBe(10_000);
-    // No model= line in a legacy/sidecar heartbeat → model is null.
-    expect(hb.model).toBeNull();
-  });
-
-  it('parses a self-reported model id from a native heartbeat (model= line)', () => {
-    const ts = new Date(NOW - 5_000).toISOString();
-    const content = `ts=${ts}\npid=42\nstatus=busy\nmodel=openai-codex/gpt-5.5:high\n`;
-    const hb = parseHeartbeat(content, NOW);
-    expect(hb.model).toBe('openai-codex/gpt-5.5:high');
-    expect(hb.status).toBe('busy');
-    expect(hb.health).toBe('healthy');
   });
 
   it('reports stale when heartbeat is older than 3×interval', () => {
@@ -867,23 +856,6 @@ describe('fleet ps — heartbeat parsing', () => {
     expect(hb.health).toBe('unknown');
     expect(hb.ts).toBeNull();
   });
-
-  it('honors MOSAIC_HEARTBEAT_INTERVAL for the freshness threshold', () => {
-    const prev = process.env.MOSAIC_HEARTBEAT_INTERVAL;
-    try {
-      // A 60s-old beat is STALE at the default 15s interval (3x15 = 45s)...
-      const ts = new Date(NOW - 60_000).toISOString();
-      const content = `ts=${ts}\npid=1\nstatus=ok\n`;
-      delete process.env.MOSAIC_HEARTBEAT_INTERVAL;
-      expect(parseHeartbeat(content, NOW).health).toBe('stale');
-      // ...but HEALTHY when the operator widened the interval to 30s (3x30 = 90s).
-      process.env.MOSAIC_HEARTBEAT_INTERVAL = '30';
-      expect(parseHeartbeat(content, NOW).health).toBe('healthy');
-    } finally {
-      if (prev === undefined) delete process.env.MOSAIC_HEARTBEAT_INTERVAL;
-      else process.env.MOSAIC_HEARTBEAT_INTERVAL = prev;
-    }
-  });
 });
 
 describe('fleet ps — systemd show parsing', () => {
@@ -2903,33 +2875,3 @@ describe('fleet init wizard', () => {
     expect(content).toContain('name: coder0');
   });
 });
-
-describe('fleet ps — heartbeat path resolution', () => {
-  const savedRunDir = process.env.MOSAIC_HEARTBEAT_RUN_DIR;
-  const savedHome = process.env.MOSAIC_HOME;
-  afterEach(() => {
-    if (savedRunDir === undefined) delete process.env.MOSAIC_HEARTBEAT_RUN_DIR;
-    else process.env.MOSAIC_HEARTBEAT_RUN_DIR = savedRunDir;
-    if (savedHome === undefined) delete process.env.MOSAIC_HOME;
-    else process.env.MOSAIC_HOME = savedHome;
-  });
-
-  it('honors MOSAIC_HEARTBEAT_RUN_DIR (matches the writer sidecar override)', () => {
-    process.env.MOSAIC_HEARTBEAT_RUN_DIR = '/run/hb';
-    expect(heartbeatPath('agent-x', '/any/home')).toBe(join('/run/hb', 'agent-x.hb'));
-  });
-
-  it('honors MOSAIC_HOME when no explicit mosaicHome is given', () => {
-    delete process.env.MOSAIC_HEARTBEAT_RUN_DIR;
-    process.env.MOSAIC_HOME = '/custom/mhome';
-    expect(heartbeatPath('agent-y')).toBe(join('/custom/mhome', 'fleet', 'run', 'agent-y.hb'));
-  });
-
-  it('falls back to <mosaicHome>/fleet/run by default', () => {
-    delete process.env.MOSAIC_HEARTBEAT_RUN_DIR;
-    delete process.env.MOSAIC_HOME;
-    expect(heartbeatPath('agent-z', '/home/u/.config/mosaic')).toBe(
-      join('/home/u/.config/mosaic', 'fleet', 'run', 'agent-z.hb'),
-    );
-  });
-});

packages/mosaic/src/commands/fleet.ts

@@ -152,16 +152,13 @@ export function resolveFleetPaths(mosaicHome = defaultMosaicHome()): FleetPaths
 }
 
 function defaultMosaicHome(): string {
-  // Honor MOSAIC_HOME so the reader matches the writer sidecar (and the launcher),
+  return join(homedir(), '.config', 'mosaic');
-  // even when MOSAIC_HOME is set in the shell without an explicit --mosaic-home flag.
-  return process.env.MOSAIC_HOME ?? join(homedir(), '.config', 'mosaic');
 }
 
 function assertDefaultMosaicHomeForSystemd(mosaicHome: string): void {
-  const literalHome = join(homedir(), '.config', 'mosaic');
+  if (resolve(mosaicHome) !== resolve(defaultMosaicHome())) {
-  if (resolve(mosaicHome) !== resolve(literalHome)) {
     throw new Error(
-      `install-systemd only supports the default Mosaic home (${literalHome}) because the user systemd units use %h/.config/mosaic paths.`,
+      `install-systemd only supports the default Mosaic home (${defaultMosaicHome()}) because the user systemd units use %h/.config/mosaic paths.`,
     );
   }
 }
@@ -371,16 +368,6 @@ export function buildAgentTailCommand(
 // ---------------------------------------------------------------------------
 
 export const HEARTBEAT_INTERVAL_MS = 15_000;
-
-/**
- * Heartbeat interval in ms, honoring MOSAIC_HEARTBEAT_INTERVAL (seconds) so the
- * `fleet ps` freshness threshold matches the writer sidecar's actual cadence
- * (start-agent-session.sh). Falls back to HEARTBEAT_INTERVAL_MS (15s).
- */
-export function heartbeatIntervalMs(): number {
-  const sec = Number.parseInt(process.env.MOSAIC_HEARTBEAT_INTERVAL ?? '', 10);
-  return Number.isFinite(sec) && sec > 0 ? sec * 1000 : HEARTBEAT_INTERVAL_MS;
-}
 export const HEARTBEAT_HEALTHY_MULTIPLIER = 3;
 
 export interface HeartbeatInfo {
@@ -390,8 +377,6 @@ export interface HeartbeatInfo {
   /** healthy | stale | unknown */
   health: 'healthy' | 'stale' | 'unknown';
   ageMs: number | null;
-  /** Model id the runtime self-reported in its heartbeat (native HB only), else null. */
-  model: string | null;
 }
 
 export interface AgentPsRow {
@@ -480,10 +465,7 @@ export function parseTmuxListSessions(output: string): string[] {
  * Returns the heartbeat file path for an agent.
  */
 export function heartbeatPath(agentName: string, mosaicHome = defaultMosaicHome()): string {
-  // Honor MOSAIC_HEARTBEAT_RUN_DIR (the writer sidecar's override); otherwise the
+  return join(mosaicHome, 'fleet', 'run', `${agentName}.hb`);
-  // canonical <mosaicHome>/fleet/run. Keeps reader and writer on the same path.
-  const runDir = process.env.MOSAIC_HEARTBEAT_RUN_DIR ?? join(mosaicHome, 'fleet', 'run');
-  return join(runDir, `${agentName}.hb`);
 }
 
 /**
@@ -492,17 +474,15 @@ export function heartbeatPath(agentName: string, mosaicHome = defaultMosaicHome(
  *   ts=<iso8601>
  *   pid=<pid>
  *   status=<ok|busy>
- *   model=<model-id>   (optional — native runtime heartbeats self-report it)
  */
 export function parseHeartbeat(content: string | null, nowMs = Date.now()): HeartbeatInfo {
   if (content === null) {
-    return { ts: null, pid: null, status: null, health: 'unknown', ageMs: null, model: null };
+    return { ts: null, pid: null, status: null, health: 'unknown', ageMs: null };
   }
   const lines = content.split('\n');
   let ts: Date | null = null;
   let pid: number | null = null;
   let status: 'ok' | 'busy' | null = null;
-  let model: string | null = null;
   for (const line of lines) {
     const [key, ...rest] = line.split('=');
     const val = rest.join('=').trim();
@@ -514,18 +494,16 @@ export function parseHeartbeat(content: string | null, nowMs = Date.now()): Hear
       if (Number.isFinite(n)) pid = n;
     } else if (key === 'status' && (val === 'ok' || val === 'busy')) {
       status = val;
-    } else if (key === 'model' && val) {
-      model = val;
     }
   }
-  const thresholdMs = heartbeatIntervalMs() * HEARTBEAT_HEALTHY_MULTIPLIER;
+  const thresholdMs = HEARTBEAT_INTERVAL_MS * HEARTBEAT_HEALTHY_MULTIPLIER;
   let health: 'healthy' | 'stale' | 'unknown' = 'unknown';
   let ageMs: number | null = null;
   if (ts !== null) {
     ageMs = nowMs - ts.getTime();
     health = ageMs <= thresholdMs ? 'healthy' : 'stale';
   }
-  return { ts, pid, status, health, ageMs, model };
+  return { ts, pid, status, health, ageMs };
 }
 
 /**
@@ -1129,7 +1107,6 @@ export function registerFleetCommand(program: Command, deps: FleetCommandDeps =
         'PID'.padEnd(8),
         'IDLE'.padEnd(8),
         'HB'.padEnd(12),
-        'MODEL'.padEnd(22),
         'FLAGS',
       ].join(' ');
       console.log(header);
@@ -1144,7 +1121,6 @@ export function registerFleetCommand(program: Command, deps: FleetCommandDeps =
           row.heartbeat.ageMs !== null
             ? `${Math.round(row.heartbeat.ageMs / 1000)}s/${row.heartbeat.health}`
             : `unknown`;
-        const model = row.heartbeat.model ?? '-';
         const flags: string[] = [];
         if (!row.managed) flags.push('UNMANAGED');
         if (row.driftFlag) flags.push('DRIFT');
@@ -1161,7 +1137,6 @@ export function registerFleetCommand(program: Command, deps: FleetCommandDeps =
             pid.padEnd(8),
             idle.padEnd(8),
             hbAge.padEnd(12),
-            model.padEnd(22),
             flags.join(','),
           ].join(' '),
         );
@@ -1453,19 +1428,15 @@ export function registerFleetAgentCommands(
 
       await runChecked(runner, buildAgentWatchCreateViewerCommand(agent, viewerName, socketName));
 
-      let exitCode = 0;
-      try {
       const [bin, args] = splitCommand(buildAgentWatchAttachCommand(viewerName, socketName));
-        exitCode = await iRunner(bin, args);
+      const exitCode = await iRunner(bin, args);
-      } finally {
+
-        // ALWAYS clean up the viewer session — even if attach threw or the process was
+      // Best-effort cleanup of the viewer session regardless of how the user detached.
-        // interrupted — so stale grouped *-watch-* sessions never accumulate. Errors here
+      // Errors here are intentionally suppressed — the agent session is unaffected.
-        // are intentionally suppressed; the agent session is unaffected.
       const killResult = await runner(
         ...splitCommand(buildAgentWatchKillViewerCommand(viewerName, socketName)),
       );
-        void killResult;
+      void killResult; // result is intentionally ignored
-      }
 
       if (exitCode !== 0) {
         process.exitCode = exitCode;

packages/mosaic/src/commands/launch.ts

@@ -291,23 +291,12 @@ function buildPrdBlock(): string {
 
 // ─── Runtime prompt builder ──────────────────────────────────────────────────
 
-/**
+function buildRuntimePrompt(runtime: RuntimeName): string {
- * Compose the full runtime contract for a harness: the resident-by-value core
- * (CONSTITUTION + AGENTS + USER + TOOLS + runtime) plus operator overlays
- * (`*.local.md` deltas), merged in precedence order so the model gets one
- * pre-merged blob (DESIGN §3.2 / R7). Overlays are injected as deltas by value;
- * base files keep their existing residency (USER injected; SOUL/STANDARDS are
- * load-on-demand, so only their small `.local` deltas are injected here).
- *
- * `mosaicHome` is parameterized for testability; production callers use the
- * module-level default.
- */
-export function composeContract(runtime: RuntimeName, mosaicHome: string = MOSAIC_HOME): string {
   const runtimeContractPaths: Record<RuntimeName, string> = {
-    claude: join(mosaicHome, 'runtime', 'claude', 'RUNTIME.md'),
+    claude: join(MOSAIC_HOME, 'runtime', 'claude', 'RUNTIME.md'),
-    codex: join(mosaicHome, 'runtime', 'codex', 'RUNTIME.md'),
+    codex: join(MOSAIC_HOME, 'runtime', 'codex', 'RUNTIME.md'),
-    opencode: join(mosaicHome, 'runtime', 'opencode', 'RUNTIME.md'),
+    opencode: join(MOSAIC_HOME, 'runtime', 'opencode', 'RUNTIME.md'),
-    pi: join(mosaicHome, 'runtime', 'pi', 'RUNTIME.md'),
+    pi: join(MOSAIC_HOME, 'runtime', 'pi', 'RUNTIME.md'),
   };
 
   const runtimeFile = runtimeContractPaths[runtime];
@@ -342,55 +331,27 @@ For required push/merge/issue-close/release actions, execute without routine con
 `);
 
   // CONSTITUTION.md (L0 — the non-negotiable law; lead with it). Tolerant of
-  // pre-constitution installs that have not been re-seeded yet. Injected by
+  // pre-constitution installs that have not been re-seeded yet.
-  // value verbatim so the bare-launch fallback read is byte-equal (R8).
+  const constitution = readOptional(join(MOSAIC_HOME, 'CONSTITUTION.md'));
-  const constitution = readOptional(join(mosaicHome, 'CONSTITUTION.md'));
   if (constitution) parts.push(constitution);
 
   // AGENTS.md
-  parts.push(readFileSync(join(mosaicHome, 'AGENTS.md'), 'utf-8'));
+  parts.push(readFileSync(join(MOSAIC_HOME, 'AGENTS.md'), 'utf-8'));
 
-  // USER.md (+ USER.local.md operator overlay, appended directly under the
+  // USER.md
-  // profile its base owns).
+  const user = readOptional(join(MOSAIC_HOME, 'USER.md'));
-  const user = readOptional(join(mosaicHome, 'USER.md'));
   if (user) parts.push('\n\n# User Profile\n\n' + user);
-  const userLocal = readOptional(join(mosaicHome, 'USER.local.md'));
-  if (userLocal.trim()) {
-    parts.push('\n\n## Operator Overlay (USER.local.md)\n\n' + userLocal);
-  }
 
   // TOOLS.md
-  const tools = readOptional(join(mosaicHome, 'TOOLS.md'));
+  const tools = readOptional(join(MOSAIC_HOME, 'TOOLS.md'));
   if (tools) parts.push('\n\n# Machine Tools\n\n' + tools);
 
-  // Operator overlays whose base layers are load-on-demand (SOUL, STANDARDS):
-  // inject only the small `.local` delta by value so the customization reaches
-  // the model without re-injecting the full base prose (preserves the byte
-  // budget). Absent `.local` files → base-only, automatically (R7 §3.2).
-  const overlayBlocks: string[] = [];
-  const soulLocal = readOptional(join(mosaicHome, 'SOUL.local.md'));
-  if (soulLocal.trim()) {
-    overlayBlocks.push('## Persona Overlay (SOUL.local.md)\n\n' + soulLocal.trim());
-  }
-  const standardsLocal = readOptional(join(mosaicHome, 'STANDARDS.local.md'));
-  if (standardsLocal.trim()) {
-    overlayBlocks.push('## Standards Overlay (STANDARDS.local.md)\n\n' + standardsLocal.trim());
-  }
-  if (overlayBlocks.length > 0) {
-    parts.push('\n\n# Operator Overlays\n\n' + overlayBlocks.join('\n\n'));
-  }
-
   // Runtime-specific contract
   parts.push('\n\n# Runtime-Specific Contract\n\n' + readFileSync(runtimeFile, 'utf-8'));
 
   return parts.join('\n');
 }
 
-/** @deprecated internal alias — use composeContract. Retained for call-site clarity. */
-function buildRuntimePrompt(runtime: RuntimeName): string {
-  return composeContract(runtime);
-}
-
 // ─── Session lock ────────────────────────────────────────────────────────────
 
 function writeSessionLock(runtime: string): void {
@@ -1015,22 +976,6 @@ export function registerLaunchCommands(program: Command): void {
     launchRuntime(runtime, extraArgs, yolo);
   });
 
-  // compose-contract — emit the composed runtime contract (base + operator
-  // overlays) for a harness to stdout, without launching. For inspection,
-  // `mosaic doctor`, diffing, and the composer test (R7).
-  program
-    .command('compose-contract <harness>')
-    .description('Print the composed runtime contract (base + *.local overlays) for a harness')
-    .action((harness: string) => {
-      const valid: RuntimeName[] = ['claude', 'codex', 'opencode', 'pi'];
-      if (!valid.includes(harness as RuntimeName)) {
-        console.error(`Unknown harness '${harness}'. Expected one of: ${valid.join(', ')}.`);
-        process.exitCode = 64;
-        return;
-      }
-      process.stdout.write(composeContract(harness as RuntimeName));
-    });
-
   // Coord (mission orchestrator)
   program
     .command('coord')