S1: scaffold squad-deps-worker (fail-closed dependency-manifest worker)

[bradygaster]

This is Slice S1 of #1748

Part of #1748

Scaffolds a dedicated squad-deps-worker agentic workflow with narrow, fail-closed dependency-manifest/lockfile authority, per Flight's APPROVED — IMPLEMENTATION-READY decision comment on #1748. This slice is deliberately inert: it adds structure and tests only, with no new PR-producing capability beyond what squad-implement-worker already has today.

What this PR does

• workflows/squad-deps-worker.md (new) — a standalone workflow_dispatch-only worker, not yet wired into squad.md's dispatch-workflow list (that's S3).
  • allowed-files is narrowly scoped to Wave 1 (npm/yarn/pnpm, NuGet CPM, Go) manifest/lockfile basenames only: package.json, package-lock.json, npm-shrinkwrap.json, yarn.lock, pnpm-lock.yaml, Directory.Packages.props, go.mod, go.sum. No broad source-file globs — this worker's entire reason to exist is that it can touch nothing else.
  • protected-files.policy: fallback-to-issue with no exclude list — every manifest write still falls back to a review issue today, identical to squad-implement-worker, which is completely unchanged by this PR.
  • excluded-files structurally strips vendored/generated content (node_modules/**, vendor/**, build output dirs) and the standard governance paths (.github/workflows/**, .github/agents/**, .github/aw/**, .squad/**) from any patch this worker could ever produce.
  • Registry/install config (NuGet.Config, bunfig.toml, .npmrc, .yarnrc.yml), SDK/tool pins (global.json), and governance docs (CODEOWNERS, SECURITY.md, CONTRIBUTING.md, CHANGELOG.md, CODE_OF_CONDUCT.md, DESIGN.md, AGENTS.md) are never in allowed-files at all, and remain in gh-aw's compiled default protected-files catalog.
• test/gh-aw-deps-worker-workflow.test.ts (new) — 8 structural/compiled/fail-closed tests:
  • Wave 1 extensionless basenames (go.mod, go.sum, yarn.lock) appear in allowed-files.
  • Narrow-authority guard: no broad source-file globs, no registry/governance basenames in allowed-files.
  • No protected-files.exclude entries yet (S2 has not landed).
  • Vendored/generated content is structurally stripped via excluded-files.
  • squad-implement-worker.md retains its unchanged exclude: [README.md]-only contract (regression guard against the general path silently gaining manifest authority).
  • Compiled (gh aw compile --strict) contract: Wave 1 manifest basenames and always-protected registry/governance basenames both still resolve to fallback-to-issue in the generated .lock.yml.
  • A mutation test (adding a manifest exclusion to squad-implement-worker.md) was run manually during development and confirmed both regression tests fail as expected, then reverted — proving these tests are not vacuous.

Explicitly deferred to follow-up slices (NOT in this PR)

• S2 — Wave 1 protected-files.exclude entries (the actual manifest-unprotect step) on squad-deps-worker.md.
• S3 — dispatcher/config routing: wiring squad-deps-worker into squad.md's dispatch-workflow list and the squadDeps opt-out key in .squad/config.json.
• S4 — dependency-change PR presentation rules: deps: title prefix, dependency-change label + provisioning, PR body evidence requirements (new-vs-update classification, frozen-install evidence, no-vendored-content confirmation).
• S5 — adoption guide / docs / setup reporting updates.

Validation

• gh aw compile squad-deps-worker --strict --no-check-update — succeeds (gh-aw v0.86.2), only the pre-existing shared-bootstrap secret warning common to every workflow importing shared/squad.md (verified identical for squad-implement-worker too).
• gh aw compile squad-implement-worker --strict --no-check-update — succeeds, unchanged.
• npx vitest run test/gh-aw-deps-worker-workflow.test.ts test/gh-aw-implement-workflow.test.ts test/gh-aw-review-workflow.test.ts — 32/32 pass (node v24.16.0, npm v11.13.0, vitest v4.1.11).
• npx tsc --noEmit for both packages/squad-sdk and packages/squad-cli (after npm run build -w packages/squad-sdk) — clean.
• git diff --check — clean.
• Confirmed pre-existing, unrelated failure in test/gh-aw-quality.test.ts ("preserves a committed cast rather than re-running init") reproduces identically with this PR's files removed — not caused by this change.

Environment note: the corporate npm proxy (packagefeedproxy.microsoft.io) does not yet mirror vite@8.2.2 pinned in package-lock.json (npm ci/npm install 404 on that exact tarball). Test validation above was completed in an earlier pass using a temporary, non-committed lockfile bypass that was fully reverted (git diff showed zero changes to package.json/package-lock.json before committing); the final commit does not touch either file. This is a pre-existing environment gap, unrelated to this change.

No merge requested — please review.

[github-actions]

🟡 Impact Analysis — PR #1882

Risk tier: 🟡 MEDIUM

📊 Summary

Metric	Count
Files changed	2
Files added	2
Files modified	0
Files deleted	0
Modules touched	2

🎯 Risk Factors

• 2 files changed (≤5 → LOW)
• 2 modules touched (2-4 → MEDIUM)

📦 Modules Affected

root (1 file)

• workflows/squad-deps-worker.md

tests (1 file)

• test/gh-aw-deps-worker-workflow.test.ts

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This report is generated automatically for every PR. See #733 for details.

[github-actions]

🛫 PR Readiness Check

ℹ️ This comment updates on each push. Last checked: commit db1f0a2

PR Scope: 🔧 Infrastructure

⚠️ 2 item(s) to address before review

Status	Check	Details
❌	Single commit	2 commits — consider squashing before review
✅	Not in draft	Ready for review
✅	Branch up to date	Up to date with dev
❌	Copilot review	No Copilot review yet — it may still be processing
✅	Changeset present	No source files changed — changeset not required
✅	Scope clean	No .squad/ or docs/proposals/ files
✅	No merge conflicts	No merge conflicts
✅	Copilot threads resolved	0 active Copilot thread(s) resolved (1 outdated skipped)
✅	CI passing	All checks passing

Files Changed (2 files, +508 −0)

File	+/−
test/gh-aw-deps-worker-workflow.test.ts	+336 −0
workflows/squad-deps-worker.md	+172 −0

Total: +508 −0

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This check runs automatically on every push. Fix any ❌ items and push again.
See CONTRIBUTING.md and PR Requirements for details.

[Copilot]

🟡 Changes recommended

One of the new contract tests uses a non-null assertion during lockfile heredoc parsing, which can produce a runtime throw instead of a diagnostic assertion on format changes.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Pull request overview

Scaffolds a new, narrowly-scoped squad-deps-worker agentic workflow intended for dependency manifest/lockfile work (Wave 1) while remaining fail-closed (no protected-files.exclude yet), and adds structural + compiled-contract tests to ensure the worker stays inert and the general implement worker doesn’t accidentally gain manifest authority.

Changes:

• Add workflows/squad-deps-worker.md as a standalone workflow_dispatch worker with a strict manifest/lockfile-only allowed-files list and structural excluded-files guardrails.
• Add test/gh-aw-deps-worker-workflow.test.ts to assert the worker remains unreachable from the dispatcher (until S3), stays fail-closed (until S2), and that compilation bakes in the expected protected/allowed/excluded contract.

File summaries

File	Description
workflows/squad-deps-worker.md	New dependency-focused worker scaffold with narrow allowed-files, fail-closed protected-files, and structural excluded-files guardrails.
test/gh-aw-deps-worker-workflow.test.ts	New tests covering scaffold invariants and compiled safe-output contract for fail-closed behavior and regression protection.

Review details

• Files reviewed: 2/2 changed files
• Comments generated: 1
• Review effort level: Lite

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