fix(commit): verify branch base is current before writing CHANGELOG

CHANGELOG.md

@@ -8,6 +8,10 @@ Please choose versions by [Semantic Versioning](http://semver.org/).
 * MINOR version when you add functionality in a backwards-compatible manner, and
 * PATCH version when you make backwards-compatible bug fixes.
 
+## Unreleased
+
+- fix(commit): add Step A.0 to Workflow A — verify the branch base is current before composing a changelog entry. On `autoRelease: true` repos your own merge cuts a release that renames `## Unreleased`, so a branch created minutes earlier is already stale and its bullets merge INTO the released section with no conflict marker. Two silent consequences: the tag and CHANGELOG disagree about what shipped, and with no `## Unreleased` left the release watcher has nothing to cut, so the work never gets released. The guard was documented in memory but nothing ran it; the command that writes CHANGELOG now does.
+
 ## v0.50.1
 
 - fix: flip the `tts-mcp#13` conventional-prefix entry from `accepted` to `rejected` in the golden set (`golden-curated-3` → `golden-curated-4`; 158 entries unchanged, 138/20 → 137/21). Verified against the PR head `59f9fe8`: `tts-mcp` declares no conventional-prefix requirement (absent from both `CLAUDE.md` and `AGENTS.md`) and its own released `v0.2.0`/`v0.1.0` CHANGELOG sections use the same prose-bullet style — a correct observation that names no defect, which the golden set's own rule rejects. It was promoted on 2026-08-18 on the strength of three-model agreement (m3+m2.7+deepseek); that reasoning was wrong because all three share a conventional-commit training prior, so agreement amplified a shared bias rather than triangulating truth. **Model agreement is not independent evidence when the models share priors** — verification has to run against the repository, not a vote. Scores computed against `golden-curated-3` credited models for reproducing a non-defect and penalised them for missing it; the entry now works as a precision probe instead

commands/commit.md

@@ -288,6 +288,37 @@ Triggered for:
 - Any feature branch with `CHANGELOG.md`
 - **Any branch (including master) when `.maintainer.yaml: release.autoRelease: true`** — `github-releaser-agent` will rename `## Unreleased` → `## vX.Y.Z` and tag within ~10 min of push.
 
+**Step A.0: Verify the branch base is current**
+
+Do this BEFORE composing any changelog entry.
+
+```bash
+cd $PROJECT_DIR && git fetch
+cd $PROJECT_DIR && git diff origin/master -- CHANGELOG.md | grep -E '^[-+]## '
+```
+
+Must print **only** `+## Unreleased`. A `-## vX.Y.Z` line means a release was cut
+after your branch point: `## Unreleased` was renamed to that version upstream, so
+your bullets will merge INTO the released section instead of a new Unreleased
+block. Git resolves this cleanly with no conflict marker — nothing warns you.
+
+Two consequences, both silent: the tag and the CHANGELOG disagree about what
+shipped, and with no `## Unreleased` left the release watcher has nothing to cut,
+so this PR's work never gets released at all.
+
+Recover by refreshing the base, then re-applying the entry:
+
+```bash
+cd $PROJECT_DIR && git reset --hard origin/master   # save your non-CHANGELOG edits first
+# re-apply the entry, then re-run the check above
+```
+
+**On `autoRelease: true` repos, run this before EVERY commit, not once per
+session.** The cut is triggered by your own merges, so merging PR-1 stales your
+base for PR-2 minutes later — no second contributor required. Observed 2026-08-26
+on `bborbe/nuke`: missed once (needed a repair PR), then caught on the next two
+commits the same afternoon by running it.
+
 **Step A.1: Pre-commit validation**
 ```bash
 make precommit  # Skip if target doesn't exist