fix(#690): promote CHANGELOG 1.3.x + gate release-notes promotion (#694)

* fix(#690): promote CHANGELOG 1.3.x + gate release-notes promotion

/gsd:update showed an empty "What's New" preview after updating to 1.3.1
because CHANGELOG.md's 1.3.x content was never promoted out of [Unreleased]
into dated sections, so `scripts/changeset/cli.cjs extract` returned exit 2
("no releases in range").

- CHANGELOG.md: split [Unreleased] into dated [1.3.0] and [1.3.1] sections
  (1.3.1 = hono advisory bump + installer-migration checksum self-heal, #670;
  1.3.0 = the feature release), restoring an empty [Unreleased].
- scripts/changeset/cli.cjs: new `verify` subcommand that exits non-zero when
  CHANGELOG has no dated `## [x.y.z]` heading for a version; hoist shared
  stripV/resolveChangelogPath helpers used by extract + verify.
- .github/workflows/release.yml: gate the finalize job on `verify` (after the
  build, before tag/publish) so an unpromoted CHANGELOG can never ship again.
- gsd-core/workflows/update.md: move `rm -f $CHANGELOG_TMP` after the
  human-readable extract re-run so the preview no longer degrades to
  "(changelog unavailable)".
- tests: regression guard for the 1.3.x headings + extract range + verify
  command coverage (present/absent/undated/v-prefixed/--json/prerelease).

Closes #690

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* chore(#690): add changeset fragment for #694

Fixed-type fragment for the user-facing /gsd:update preview fix and the
release-notes promotion gate.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

CHANGELOG.md

@@ -6,6 +6,18 @@ Format follows [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
 ## [Unreleased]
 
+## [1.3.1](https://www.npmjs.com/package/@opengsd/gsd-core/v/1.3.1) - 2026-06-04
+
+### Security
+
+- **Bumped `hono` to clear a moderate npm advisory** carried transitively in the dependency tree. (#670)
+
+### Fixed
+
+- **Installer-migration checksum drift no longer blocks upgrades** — the updater now self-heals when a shipped migration's recorded checksum has drifted, reconciling the stored checksum instead of aborting. Restores upgrades across all OSes after shipped migration bodies were edited in a prior release. (#670)
+
+## [1.3.0](https://www.npmjs.com/package/@opengsd/gsd-core/v/1.3.0) - 2026-06-04
+
 ### Added
 
 - **Vertical MVP Slice mode** — `--mvp` flag on `/gsd-plan-phase` switches the planner from horizontal layer decomposition to vertical feature-slice decomposition (UI→API→DB in one task sequence). On Phase 1 of a new project with no prior phase summaries, also emits `SKELETON.md` via Walking Skeleton mode. Composable with `--tdd`: `--mvp --tdd` produces vertical slices where every behavior-adding task starts with a failing test. Phase-level persistence via `**Mode:** mvp` in ROADMAP.md applies `--mvp` automatically without the flag. (#78)