docs(l0): declaration grammar moves to .mosaic/repo.json (#1216)

Amendment per operator GO (ms-grill-me design round, 2026-08-20):

- Declaration is .mosaic/repo.json under integration_trunk, not a
  byte-exact AGENTS.md line. Unknown/misspelled keys and unparsable
  files are a structural hard stop; no prose grammar to near-miss
  (Q15 answer, plan D3/D9).
- Changing an existing declaration is operator-owned, above ordinary
  PR review (SF2, plan D10).
- Seeds this repo's declaration: integration_trunk next,
  release_branch main — prevents the absent-declaration default from
  rebinding the stack to main at land time.
- Gloss references in BOOTSTRAP/CODE-REVIEW/CI-CD-PIPELINES point at
  repo.json; merge of origin/next restores pinned-image CI coverage
  for this pre-pin branch (D27 caveat).

.mosaic/repo.json

@@ -0,0 +1,4 @@
+{
+  "integration_trunk": "next",
+  "release_branch": "main"
+}

packages/mosaic/framework/defaults/AGENTS.md

@@ -84,6 +84,7 @@ is re-seeded a genuinely missing core file is a stop-and-report condition — no
 
 Confirm: required + situational tests passed (primary gate); aligned to `docs/PRD.md`; acceptance
 criteria mapped to evidence; independent code review passed (if code changed); required docs updated;
-scratchpad updated. For PR-workflow delivery: merged PR number + merge commit on `main`, terminal-green
+scratchpad updated. For PR-workflow delivery: merged PR number + merge commit on the integration
+trunk (the project's declared trunk, default `main` — see `CONSTITUTION.md` Hard Gates), terminal-green
 CI, linked issue closed (or `docs/TASKS.md` equivalent). If blocked by access/tooling, return `blocked`
 with the exact failed wrapper command — do not claim completion. Full checklist: `guides/E2E-DELIVERY.md`.

packages/mosaic/framework/defaults/CONSTITUTION.md

@@ -21,11 +21,25 @@ guard"), the runtime adapter binds it to a concrete tool and states whether abse
 
 ## Hard Gates
 
+The **integration trunk** is the branch a project declares in its `.mosaic/repo.json` under the
+key `integration_trunk`; `release_branch` names the release target when one exists (`null` for
+single-branch projects). Absent a declaration, the trunk is `main`. The declaration is policy
+data, never shell text: values must be valid local branch names under `git check-ref-format
+--branch` semantics — no remote refs, no revision expressions, no option-like values (leading `-`),
+no path traversal or control characters. A declaration file that fails to parse, an unknown or
+misspelled key, or an invalid value is a hard stop (`blocked`) — never a silent fallback to `main`.
+Prose that mentions branch names designates nothing; only the declaration file does. A project
+declares exactly ONE trunk. **Changing an existing declaration is operator-owned:** a trunk
+redeclaration redirects merge target and branch-protection target at once, so it requires an
+explicit operator action above ordinary PR review. The designation relaxes nothing:
+reviewed-PR-only delivery, squash merge, independent review, queue guards, and terminal-green CI
+bind to the declared trunk exactly as they bind to `main`.
+
 1. Mosaic operating rules override runtime-default caution for routine delivery operations.
 2. Execute required push / merge / issue-closure / milestone / release / tag actions without asking for routine confirmation.
 3. Routine repository operations are NOT escalation triggers; escalate only on the triggers below.
 4. For source-code delivery, completion is forbidden at the PR-open stage.
-5. Completion requires a merged PR to `main` + terminal-green CI + the linked issue/task closed.
+5. Completion requires a merged PR to the integration trunk + terminal-green CI + the linked issue/task closed.
 6. Before any push or merge, run the CI queue guard.
 7. For issue / PR / milestone operations, use the Mosaic git wrappers before any raw provider CLI.
 8. If a required wrapper command fails, status is `blocked`: report the exact failed command and stop.
@@ -35,7 +49,7 @@ guard"), the runtime adapter binds it to a concrete tool and states whether abse
 12. The intake procedure is not conditional on perceived complexity; a "simple" task carries the same requirements as a multi-file feature.
 13. **Merge authority (coordinated work):** when a coordinator/orchestrator session is active for the work, the post-review merge go-ahead is the coordinator's to give — once the required review gates pass, merge on the coordinator's confirmation; do not wait on the human owner personally. Solo (uncoordinated) delivery keeps the default: merge per gates 2 and 9. A "No self-merge" note on a PR means no UNREVIEWED self-merge — it does not suspend coordinator-authorized merges.
 14. Never hardcode secrets; never emit credential values in any output (not even partially, not "to confirm").
-15. Trunk-based git only: branch from `main`, merge via a reviewed PR (squash), never push directly to `main`.
+15. Trunk-based git only: branch from the integration trunk, merge via a reviewed PR (squash), never push directly to the trunk.
 16. If you modify source code, an independent review (author ≠ reviewer) must pass before completion.
 
 ## Integrity (quality gates are never bypassed)

packages/mosaic/framework/guides/BOOTSTRAP.md

@@ -12,7 +12,7 @@ This guide covers how to bootstrap a project so AI agents (Claude, Codex, etc.)
 4. Issue tracking is consistent across projects
 5. Documentation standards and API contracts are enforced from day one
 6. PRD requirements are established before coding begins
-7. Branching/merging is consistent: `branch -> main` via PR with squash-only merges
+7. Branching/merging is consistent: branch -> integration trunk (default `main`) via PR with squash-only merges
 8. Steered-autonomy execution is enabled so agents can run end-to-end with escalation-only human intervention
 
 ## Agent Host Prerequisites
@@ -206,7 +206,7 @@ Every runtime context file should contain:
 6. **Issue tracking** — Issue and commit conventions
 7. **Code review** — Required review process
 8. **Runtime notes** — Runtime-specific behavior references
-9. **Branch and merge policy** — Trunk workflow (`branch -> main` via PR, squash-only)
+9. **Branch and merge policy** — Trunk workflow (branch -> integration trunk via PR, squash-only)
 10. **Autonomy and escalation policy** — Agent owns coding/review/PR/release/deploy lifecycle
 
 ---
@@ -288,15 +288,17 @@ Reserve `0.1.0` for the MVP release milestone.
 
 ---
 
-## Step 5b: Configure Main Branch Protection (Hard Rule)
+## Step 5b: Configure Trunk Branch Protection (Hard Rule)
 
-Apply equivalent settings in Gitea, GitHub, or GitLab:
+Apply equivalent settings in Gitea, GitHub, or GitLab, targeting the project's integration trunk
+(the branch its `.mosaic/repo.json` declares under `integration_trunk`; default `main` — see
+`CONSTITUTION.md` Hard Gates):
 
-1. Protect `main` from direct pushes.
-2. Require pull requests to merge into `main`.
+1. Protect the integration trunk from direct pushes.
+2. Require pull requests to merge into the integration trunk.
 3. Require required CI/status checks to pass before merge.
 4. Require code review approval before merge.
-5. Allow **squash merge only** for PRs into `main` (disable merge commits and rebase merges for `main`).
+5. Allow **squash merge only** for PRs into the integration trunk (disable merge commits and rebase merges for it).
 
 This enforces one merge strategy across human and agent workflows.
 
@@ -513,9 +515,9 @@ After bootstrapping, verify:
 - [ ] Git labels created (epic, feature, bug, task, etc.)
 - [ ] Initial pre-MVP milestone created (0.0.1)
 - [ ] MVP milestone reserved for release (0.1.0)
-- [ ] `main` is protected from direct pushes
-- [ ] PRs into `main` are required
-- [ ] Merge method for `main` is squash-only
+- [ ] The integration trunk is protected from direct pushes
+- [ ] PRs into the integration trunk are required
+- [ ] Merge method for the integration trunk is squash-only
 - [ ] Quality gates run successfully
 - [ ] `.env.example` exists (if project uses env vars)
 - [ ] CI/CD pipeline configured (if using Woodpecker/GitHub Actions)

packages/mosaic/framework/guides/CI-CD-PIPELINES.md

@@ -4,6 +4,11 @@
 
 ## Overview
 
+> **Integration trunk:** the YAML examples in this guide use the default integration trunk `main`
+> in branch conditions and version rules. A project that declares a different trunk in its
+> `.mosaic/repo.json` under `integration_trunk` (see `CONSTITUTION.md` Hard Gates) substitutes its
+> declared trunk wherever `main` appears as the trunk branch.
+
 This guide covers the canonical CI/CD pattern used across projects. The pipeline runs in Woodpecker CI and follows this flow:
 
 ```
@@ -865,7 +870,7 @@ steps:
    ```yaml
    image: git.example.com/org/service@${IMAGE_DIGEST}
    ```
-7. **Test on a short-lived non-main branch first** — open a PR and verify quality gates before merging to `main`
+7. **Test on a short-lived non-trunk branch first** — open a PR and verify quality gates before merging to the integration trunk
 8. **Verify images appear** in Gitea Packages tab after successful pipeline
 
 ## Terminal-Green Full-Step Contract
@@ -906,7 +911,7 @@ For source-code delivery, completion is not allowed at "PR opened" stage.
 
 Required sequence:
 
-1. Merge PR to `main` (squash) via Mosaic wrapper.
+1. Merge PR to the integration trunk (squash) via Mosaic wrapper.
 2. Monitor CI to terminal status:
    ```bash
    ~/.config/mosaic/tools/git/pr-ci-wait.sh -n <PR_NUMBER>
@@ -1112,5 +1117,5 @@ If a project currently uses Verdaccio (e.g., U-Connect at `npm.uscllc.net`), fol
 
 ### Pipeline runs Docker builds on pull requests
 
-- Verify `when` clause on Docker build steps restricts to `branch: [main]`
+- Verify `when` clause on Docker build steps restricts to the integration trunk (`branch: [main]` by default)
 - Pull requests should only run quality gates, not build/push images

packages/mosaic/framework/guides/CODE-REVIEW.md

@@ -10,9 +10,10 @@ If implementation diverges from `docs/PRD.md` or `docs/PRD.json` without PRD upd
 
 Merge strategy enforcement (HARD RULE):
 
-- PR target for delivery is `main`.
-- Direct pushes to `main` are prohibited.
-- Merge to `main` MUST be squash-only.
+- The integration trunk is the branch the project's `.mosaic/repo.json` declares under `integration_trunk` (default: `main`) — see `CONSTITUTION.md` Hard Gates.
+- PR target for delivery is the integration trunk.
+- Direct pushes to the integration trunk are prohibited.
+- Merge to the integration trunk MUST be squash-only.
 - Use `~/.config/mosaic/tools/git/pr-merge.sh -n {PR_NUMBER} -m squash --expect-head {approved_full_sha}` (or PowerShell equivalent).
 
 An estate MAY carry a documented exception for a repository whose gates are commit hooks rather
@@ -65,6 +66,19 @@ Each of these produced a wrong conclusion before it was written down.
     conclusion drawn from it describes the wrong tree. Confirm `git rev-parse --show-toplevel`
     is the tree you think it is before trusting any git output.
 
+13. **Run the repository's PINNED tool version.** `npx <tool>` resolves a local `node_modules`
+    install when one is present and fetches the latest release when one is not, so the same
+    command answers differently depending on where it ran. A reviewer measuring in a fresh clone
+    or a detached worktree — which is exactly where reviewers measure — has no `node_modules` and
+    silently gets the latest release instead of the pinned one. Measured on mosaicstack#1313: the
+    lockfile pins prettier 3.8.1, under which three guides pass; a version-less `npx` in a
+    worktree resolved 3.9.6, under which the same three fail; and 3.0.0, the floor of the declared
+    `^3.0.0` range, fails a different one. Three versions, three verdicts, identical bytes. Use
+    `node_modules/.bin/<tool>`, or name the version the lockfile pins.
+14. **A formatter or linter declared as a range is a dated verdict, not a fact.** If a lockfile
+    pins it, the gate is reproducible today and will disagree with itself the day the pin moves.
+    Report a formatting failure with the version that produced it, always.
+
 ### Feedback Categories
 
 - **Blocker**: must fix before merge (security, bugs, test failures)
@@ -184,8 +198,8 @@ Use `~/.config/mosaic/templates/docs/DOCUMENTATION-CHECKLIST.md` whenever code/A
 # List the issue being addressed
 ~/.config/mosaic/tools/git/issue-list.sh -i {issue-number}
 
-# View the changes
-git diff main...HEAD
+# View the changes (diff against the integration trunk; default: main)
+git diff {integration_trunk}...HEAD
 ```
 
 ### Providing Feedback
@@ -214,4 +228,4 @@ This pattern appears in 3 places. A shared helper would reduce duplication.
 2. If changes requested, assign back to author
 3. If approved, note approval in issue comments
 4. For merges, ensure CI passes first
-5. Merge PR to `main` with squash strategy only
+5. Merge PR to the integration trunk with squash strategy only

packages/mosaic/framework/guides/E2E-DELIVERY.md

@@ -78,7 +78,7 @@ For implementation work, you MUST run this cycle in order:
 7. `commit` - commit only when the logical unit passes tests and review.
 8. `pre-push queue guard` - before pushing, wait for running/queued project pipelines to clear: `~/.config/mosaic/tools/git/ci-queue-wait.sh --purpose push`.
 9. `push` - push immediately after queue guard passes.
-10. `PR integration` - if external git provider is available, create/update PR to `main` and merge with required strategy via Mosaic wrappers.
+10. `PR integration` - if external git provider is available, create/update PR to the integration trunk (the project's declared trunk, default `main`) and merge with required strategy via Mosaic wrappers.
 11. `pre-merge queue guard` - before merging PR, wait for running/queued project pipelines on the exact PR head to clear: `~/.config/mosaic/tools/git/ci-queue-wait.sh --purpose merge -B <PR_HEAD_BRANCH> -R <PR_HEAD_OWNER/REPO> --sha <PR_HEAD_FULL_SHA>`.
 12. `CI/pipeline verification` - wait for terminal CI status and require green before completion (`~/.config/mosaic/tools/git/pr-ci-wait.sh` for PR-based workflow).
 13. `issue closure` - close linked external issue (or close internal `docs/TASKS.md` task ref when provider is unavailable).
@@ -199,7 +199,7 @@ Before running this checklist, pause and self-interrogate: did I fulfill the use
 10. No unresolved blocker hidden.
 11. If deployment is in scope, deployment target, release version, and post-deploy verification evidence are documented.
 12. `docs/TASKS.md` status and issue/internal references are updated to match delivered work.
-13. If source code changed and external provider is available: PR merged to `main` (squash), with merge evidence recorded.
+13. If source code changed and external provider is available: PR merged to the integration trunk (squash), with merge evidence recorded.
 14. CI/pipeline status is terminal green for the merged PR/head commit.
 15. Linked external issue is closed (or internal task ref is closed when no provider exists).
 16. If any of items 13-15 fail due access/tooling, report `blocked` with exact failed wrapper command and do not claim completion.

packages/mosaic/framework/guides/ORCHESTRATOR-PROTOCOL.md

@@ -253,7 +253,7 @@ status → mission → run → repeat
 
 - [ ] All milestone tasks in TASKS.md are `done`
 - [ ] CI/pipeline green
-- [ ] PR merged to `main`
+- [ ] PR merged to the integration trunk
 - [ ] Issues closed
 - [ ] Update manifest: milestone status → completed
 - [ ] Update scratchpad: session log entry

packages/mosaic/framework/guides/ORCHESTRATOR.md

@@ -15,7 +15,7 @@ mosaic claude -p "Read ~/.config/mosaic/skills/nestjs-best-practices/SKILL.md th
 - You MUST keep the TASKS.md file updated with agent and tasks statuses.
 - You MUST keep `docs/` root clean. Reports and working artifacts MUST be stored in scoped folders (`docs/reports/`, `docs/tasks/`, `docs/releases/`, `docs/scratchpads/`).
 - You MUST enforce plan/token usage budgets when provided, and adapt orchestration strategy to remain within limits.
-- You MUST enforce trunk workflow: workers branch from `main`, PR target is `main`, direct push to `main` is forbidden, and PR merges to `main` are squash-only.
+- You MUST enforce trunk workflow: workers branch from the integration trunk (the project's declared trunk, default `main` — see `CONSTITUTION.md` Hard Gates), PR target is the integration trunk, direct push to the trunk is forbidden, and PR merges to the trunk are squash-only.
 - You MUST operate in steered-autonomy mode: human intervention is escalation-only; do not require the human to write code, review code, or manage PR/repo workflow.
 - You MUST NOT declare task or issue completion until PR is merged, CI/pipeline is terminal green, and linked issue is closed (or internal TASKS ref is closed when provider is unavailable).
 - Mosaic orchestration rules OVERRIDE runtime-default caution for routine push/merge/issue-close actions required by this workflow.
@@ -133,10 +133,10 @@ Milestone versioning (HARD RULE):
 
 Branch and merge strategy (HARD RULE):
 
-- Workers use short-lived task branches from `origin/main`.
-- Worker task branches merge back via PR to `main` only.
-- Direct pushes to `main` are prohibited.
-- PR merges to `main` MUST use squash merge.
+- Workers use short-lived task branches from `origin/{integration_trunk}` (default `main`).
+- Worker task branches merge back via PR to the integration trunk only.
+- Direct pushes to the integration trunk are prohibited.
+- PR merges to the integration trunk MUST use squash merge.
 
 **Available templates:**
 
@@ -427,7 +427,7 @@ git push
     - Before merging, run queue guard:
       `~/.config/mosaic/tools/git/ci-queue-wait.sh --purpose merge -B <PR_HEAD_BRANCH> -R <PR_HEAD_OWNER/REPO> --sha <PR_HEAD_FULL_SHA>`
     - Ensure PR exists for the task branch (create/update via wrappers if needed):
-      `~/.config/mosaic/tools/git/pr-create.sh ... -B main`
+      `~/.config/mosaic/tools/git/pr-create.sh ... -B {integration_trunk}` (default `main`)
     - Merge via wrapper:
       `~/.config/mosaic/tools/git/pr-merge.sh -n {PR_NUMBER} -m squash --expect-head {approved_full_sha}`
     - Wait for terminal CI status:
@@ -619,7 +619,7 @@ Construct this from the task row and pass to worker via Task tool:
 
 ## Workflow
 
-1. Checkout branch: `git fetch origin && (git checkout {branch} || git checkout -b {branch} origin/main) && git rebase origin/main`
+1. Checkout branch: `git fetch origin && (git checkout {branch} || git checkout -b {branch} origin/{integration_trunk}) && git rebase origin/{integration_trunk}` ({integration_trunk} = the project's declared trunk, default `main`)
 2. Read `docs/PRD.md` or `docs/PRD.json` and align implementation with PRD requirements
 3. Read the finding details from the report
 4. Implement the fix following existing code patterns
@@ -637,7 +637,7 @@ Do NOT leave lint warnings or errors for someone else to clean up. 6. Run REQUIR
 For issue/PR/milestone operations, use scripts (NOT raw tea/gh):
 
 - `~/.config/mosaic/tools/git/issue-view.sh -i {N}`
-- `~/.config/mosaic/tools/git/pr-create.sh -t "Title" -b "Desc" -B main`
+- `~/.config/mosaic/tools/git/pr-create.sh -t "Title" -b "Desc" -B {integration_trunk}`
 - Push: `~/.config/mosaic/tools/git/ci-queue-wait.sh --purpose push -B {task_branch}`
 - Merge: `~/.config/mosaic/tools/git/ci-queue-wait.sh --purpose merge -B {pr_head_branch} -R {pr_head_owner/repo} --sha {pr_head_full_sha}`
 - `~/.config/mosaic/tools/git/pr-merge.sh -n {PR_NUMBER} -m squash --expect-head {approved_full_sha}`
@@ -994,13 +994,13 @@ mv docs/reports/qa-automation/pending/*failing-file* docs/reports/qa-automation/
 
 ---
 
-## Merge-to-Main Candidate Protocol (Container Deployments)
+## Merge-to-Trunk Candidate Protocol (Container Deployments)
 
-If deployment is in scope and container images are used, every merge to `main` MUST execute this protocol:
+If deployment is in scope and container images are used, every merge to the integration trunk MUST execute this protocol:
 
 1. Build and push immutable candidate image tags:
    - `sha-<shortsha>` (always)
-   - `v{base-version}-rc.{build}` (for `main` merges)
+   - `v{base-version}-rc.{build}` (for integration-trunk merges)
    - `testing` mutable pointer to the same digest
 2. Resolve and record the image digest for each service.
 3. Deploy by digest to testing environment (never deploy by mutable tag alone).

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

@@ -292,16 +292,6 @@ esac
 _build_runtime_bin_prefix() {
   local candidates=()
   if [ -n "$MOSAIC_RUNTIME_BIN" ]; then candidates+=("$MOSAIC_RUNTIME_BIN"); fi
-  # A host with no system Node gets one bootstrapped here by tools/install.sh, which
-  # records it in ~/.profile. The fleet unit runs `env -i ... bash --noprofile --norc`
-  # by design, so ~/.profile is never read and the directory has to be named here.
-  # The npm probe below cannot cover this: it reports a package prefix
-  # (~/.npm-global), never a Node runtime directory. It sits ahead of the npm probe so
-  # the bootstrapped runtime wins on a host that has both — that is the one the installer
-  # verified — while an explicit MOSAIC_RUNTIME_BIN still outranks it.
-  # Runtime binaries are `#!/usr/bin/env node`, so without this the pane resolves the
-  # binary and then dies on `env: 'node': No such file or directory`.
-  candidates+=("$PANE_HOME/.mosaic/node/current/bin")
   if command -v npm >/dev/null 2>&1; then
     local npm_prefix
     npm_prefix=$(npm config get prefix 2>/dev/null) || true

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

@@ -520,93 +520,6 @@ for blocked in LD_PRELOAD= BASH_ENV= MOSAIC_UNTRUSTED_SENTINEL=; do
   contains_literal "$pane_environment" "$blocked" && fail "runtime pane received $blocked"
 done
 
-# #1256. On a host with no system Node, tools/install.sh bootstraps one into
-# ~/.mosaic/node/ and writes that directory to ~/.profile. The fleet unit runs
-# `env -i ... bash --noprofile --norc`, so ~/.profile is never read — correctly, by
-# design — and _build_runtime_bin_prefix does not list the bootstrap directory. Its
-# `npm config get prefix` branch cannot cover the gap either: the installer points
-# npm's prefix at ~/.npm-global, so that branch contributes the npm-global directory
-# and never the Node one, however it resolves.
-#
-# The property under test is not "the string is in PATH". It is that the pane can
-# EXECUTE a Node-shebang runtime binary — which is what `mosaic` is
-# (`#!/usr/bin/env node`) and what actually failed: measured on a greenfield VM as
-# `env: 'node': No such file or directory` after a clean install that reported success.
-#
-# So this case runs the pane for real and requires it to have run. A PATH-substring
-# assertion would pass on a fix that put the directory in the wrong position, and it
-# would keep passing if the pane later stopped running for some unrelated reason.
-: > "$TMUX_CALLS"
-HOME_NODE="$ROOT/bootstrap-node/.config/mosaic"
-write_generated "$HOME_NODE" "coder-node"
-NODE_PANE_HOME="${HOME_NODE%/.config/mosaic}"
-NODE_BOOTSTRAP_BIN="$NODE_PANE_HOME/.mosaic/node/current/bin"
-mkdir -p "$NODE_BOOTSTRAP_BIN"
-
-# The bootstrapped runtime. It records that it ran, which is the evidence this case
-# turns on: no node reachable from the pane means no marker.
-cat > "$NODE_BOOTSTRAP_BIN/node" <<'SHIM'
-#!/usr/bin/env bash
-set -euo pipefail
-env -0 > "${MOSAIC_HOME:?}/fleet/pane-environment"
-SHIM
-chmod +x "$NODE_BOOTSTRAP_BIN/node"
-
-# write_generated plants its symlinks under the MOSAIC_HOME it is given; here the
-# pane's HOME is the trusted parent, so the pane's view of "installed" is this
-# directory instead. `pi` is what #1241 resolves against PANE_PATH; `mosaic` is what
-# the pane then executes, and it is a Node script — not a bash script that would run
-# anywhere and quietly hide the defect.
-mkdir -p "$NODE_PANE_HOME/.npm-global/bin"
-ln -sf "$FAKE_BIN/pi" "$NODE_PANE_HOME/.npm-global/bin/pi"
-printf '#!/usr/bin/env node\n' > "$NODE_PANE_HOME/.npm-global/bin/mosaic"
-chmod +x "$NODE_PANE_HOME/.npm-global/bin/mosaic"
-
-# The npm branch is modelled ALIVE and still cannot close the gap, which is the
-# stronger statement. An earlier draft of this case tried to model npm as absent —
-# true on a real bootstrap host, where npm lives only in the Node directory — and it
-# refused to run anywhere npm is in the system path, i.e. most machines. It was also
-# the weaker claim: it would have proven only that a dead branch supplies nothing.
-#
-# On a bootstrap host the installer sets npm's prefix to ~/.npm-global. So even with
-# `command -v npm` true and the branch executing, `npm config get prefix` yields the
-# npm-global directory and never the Node one. The gap does not depend on whether
-# that branch runs.
-NODE_LAUNCHER_BIN="$ROOT/bootstrap-node-launcher-bin"
-mkdir -p "$NODE_LAUNCHER_BIN"
-ln -sf "$FAKE_BIN/tmux" "$NODE_LAUNCHER_BIN/tmux"
-ln -sf "$FAKE_BIN/npm" "$NODE_LAUNCHER_BIN/npm"
-
-/usr/bin/env -i \
-  "HOME=$NODE_PANE_HOME" \
-  "PATH=$NODE_LAUNCHER_BIN:/usr/bin:/bin" \
-  "MOSAIC_HOME=$HOME_NODE" \
-  "MOSAIC_TEST_TMUX_CALLS=$TMUX_CALLS" \
-  "MOSAIC_TEST_HOME=$NODE_PANE_HOME" \
-  "MOSAIC_TEST_NPM_PREFIX=$NODE_PANE_HOME/.npm-global" \
-  MOSAIC_TEST_FLEET_OWNER=123e4567-e89b-12d3-a456-426614174000 \
-  MOSAIC_TEST_EXECUTE_PANE=1 \
-  "MOSAIC_TEST_PANE_PID=$$" \
-  "$START" coder-node
-
-[ -f "$HOME_NODE/fleet/pane-environment" ] || \
-  fail "pane could not execute a Node-shebang runtime: $NODE_BOOTSTRAP_BIN is absent from PANE_PATH (#1256)"
-node_pane_environment=$(tr '\0' '\n' < "$HOME_NODE/fleet/pane-environment")
-# Colon-pad and match a whole element. A regex with `(^|:)` after `.*` looks like it
-# does this and does not: an anchor cannot match mid-pattern, so it silently requires
-# a leading colon and rejects the directory in FIRST position — which is where THIS
-# FIXTURE puts it: it runs under `env -i` with no MOSAIC_RUNTIME_BIN, so the bootstrap
-# directory leads. That is a property of the fixture, not of the fix — in general the
-# directory sits second, after MOSAIC_RUNTIME_BIN. The colon padding makes the
-# assertion position-independent either way, which is why it is written this way and
-# not with an anchor. That produced a failure reading "pane ran but PANE_PATH does not
-# carry <dir>" against a PATH whose first element was that dir.
-node_pane_path=":$(printf '%s\n' "$node_pane_environment" | sed -n 's/^PATH=//p' | head -1):"
-case "$node_pane_path" in
-  *":$NODE_BOOTSTRAP_BIN:"*) ;;
-  *) fail "pane ran but PANE_PATH does not carry $NODE_BOOTSTRAP_BIN (PATH=$node_pane_path)" ;;
-esac
-
 write_interaction_generated() {
   local home="$1"
   local agent="$2"