docs: name the CHANGELOG prose-lint gate and the Blast radius body section in the contributor docs

Co-authored-by: capy-ai[bot] <230910855+capy-ai[bot]@users.noreply.github.com>

CONTRIBUTING.md

@@ -621,7 +621,7 @@ A GitHub Action (`.github/workflows/skill-docs.yml`) generates all hosts on push
 
 Supply-chain gates run alongside it:
 
-- **Quality gate** (`.github/workflows/quality-gate.yml`, every PR and push) — scans the diff's added lines for credentials using gstack's own redact engine (`.github/scripts/gate-secret-scan.mjs`). HIGH findings fail the job; MEDIUM findings surface as an advisory count. Fails closed if the scan can't produce a report. Also runs ShellCheck on the setup/build boundaries.
+- **Quality gate** (`.github/workflows/quality-gate.yml`, every PR and push) — scans the diff's added lines for credentials using gstack's own redact engine (`.github/scripts/gate-secret-scan.mjs`). HIGH findings fail the job; MEDIUM findings surface as an advisory count. Fails closed if the scan can't produce a report. Also runs ShellCheck on the setup/build boundaries, and gates the `## [Unreleased]` block of `CHANGELOG.md` with `bin/gstack-prose-lint CHANGELOG.md --unreleased --gate` (autopilot vocabulary, "not just X, but Y" and the other tells it names; a stamped or absent block passes; fixes in [docs/troubleshooting.md](docs/troubleshooting.md#prose-lint-found)).
 - **Dependency review** (`.github/workflows/dependency-review.yml`) — reviews dependency changes on PRs that touch `package.json` or `bun.lock` files and fails on high or critical advisories. It and the weekly OSV scan are the dependency gates.
 - **OSV scanner** (`.github/workflows/osv-scanner.yml`) — weekly vulnerability scan against the OSV database. Config lives in `.osv-scanner.toml` and is loaded via an explicit `--config` flag (OSV does not auto-discover that filename); every ignore entry needs a reason and an `ignoreUntil` expiry, enforced by `test/osv-config-wiring.test.ts`. A failed main scan upserts the tracking issue "OSV scanner: vulnerable dependency needs triage" and a clean scan closes it; `test/osv-ignore-expiry.test.ts` fails 14 days before any `ignoreUntil`, so an expiring suppression surfaces in a PR.
 - **Weekly test health** (`.github/workflows/test-health.yml`, Mondays and on dispatch) — runs `bun run test:health --since-days 7 --enforce`. It fails when a free test file flakes in more than 5% of at least 20 main runs or more than 5 free files are missing from the duration seed, upserts one tracking issue on failure and closes it only when every previously failing check has evidence and passes. Metrics it cannot read print "unavailable: <reason>; next: <step>" and never fail the run.

docs/CHANGELOG_STYLE.md

@@ -62,6 +62,9 @@ the user gets; the path to that system is invisible to them.
 **When to write the CHANGELOG entry:**
 - At `/ship` time (Step 13), not during development or mid-branch.
 - The entry covers ALL commits on this branch vs the base branch.
+- `/ship` lints the lines the branch added with `bin/gstack-prose-lint CHANGELOG.md --base origin/<base> --gate`,
+  and the Quality gate workflow gates the `## [Unreleased]` block the same way. Rewrite each `PROSE:` line
+  it names ([docs/troubleshooting.md](troubleshooting.md#prose-lint-found)).
 - Never fold new work into an existing CHANGELOG entry from a prior version that
   already landed on main. If main has v0.10.0.0 and your branch adds features,
   bump to v0.10.1.0 with a new entry — don't edit the v0.10.0.0 entry.

docs/PROJECT_STRUCTURE.md

@@ -95,7 +95,7 @@ gstack/
 ├── docs/designs/    # Design documents (incl. IMPECCABLE_INTEROP.md = the design detector / catalog / open DESIGN.md record, and fork-port-residual-2026-09/ evaluation evidence)
 ├── setup-deploy/    # /setup-deploy skill (one-time deploy config)
 ├── .github/         # CI workflows + shared composite actions (.github/actions/) + Docker image (claude CLI pinned)
-│   ├── workflows/   # evals.yml (E2E on Ubicloud), quality-gate.yml (secret scan), dependency-review.yml, osv-scanner.yml, skill-docs.yml, actionlint.yml, plus free-tests, Windows, periodic and marathon evals, CSO release, platform qualification and smaller gates
+│   ├── workflows/   # evals.yml (E2E on Ubicloud), quality-gate.yml (secret scan, CHANGELOG prose lint), dependency-review.yml, osv-scanner.yml, skill-docs.yml, actionlint.yml, plus free-tests, Windows, periodic and marathon evals, CSO release, platform qualification and smaller gates
 │   └── docker/      # Dockerfile.ci (pre-baked toolchain + Playwright/Chromium)
 ├── contrib/         # Contributor-only tools (never installed for users)
 │   └── add-host/    # /gstack-contrib-add-host skill
@@ -103,7 +103,7 @@ gstack/
 ├── SKILL.md         # Generated from SKILL.md.tmpl (don't edit directly)
 ├── SKILL.md.tmpl    # Template: edit this, run gen:skill-docs
 ├── ETHOS.md         # Builder philosophy (Boil the Ocean, Search Before Building)
-├── NOTICE.md        # Third-party notices: material derived from impeccable and the DESIGN.md spec (Apache-2.0), Elaya's design skills and hallmark's sloplint (MIT)
+├── NOTICE.md        # Third-party notices: material derived from impeccable and the DESIGN.md spec (Apache-2.0), Elaya's design skills and hallmark's sloplint (MIT), plus courtesy entries for tstack and pstack ideas and word lists (MIT; no license text carried)
 ├── licenses/        # Verbatim license texts for the notices above (Apache-2.0.txt, MIT-elaya.txt, MIT-hallmark.txt)
 └── package.json     # Build scripts for browse
 ```

docs/captain.md

@@ -165,7 +165,7 @@ a push included. The sequence that works unattended on Capy:
    to the current tree.
 6. Docs audit: snapshot the documentation candidates read-only and record the vetted
    section.
-7. Body and receipt: compose the PR body (What changed, Why, Approvals first on Capy),
+7. Body and receipt: compose the PR body (What changed, Why, Blast radius, Approvals first on Capy),
    write the ship receipt into it, post body and title.
 8. Terminal line: `gstack-ship-receipt result --pr <n>` prints
    `GSTACK_RESULT: skill=ship status=complete`.