refactor(test): fold ship PR-title skeleton guard into carve-guard registry

main shipped a generalized carve-guard system (PR #1907) that is now the single
source of truth for carved-skill skeleton invariants. Register the PR-title rule
there instead of a standalone test: ship's mustStayInSkeleton asserts v$NEW_VERSION
+ the rewrite helper stay always-loaded, and mustMoveToSection asserts both the
create and update PR paths stay carved into pr-body.md (present in the union, out of
the skeleton). Delete the standalone ship-pr-title-version-always-loaded test it
replaces. The CI-workflow safety tripwire stays standalone (not a carve concern).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

test/helpers/carve-guards.ts

@@ -106,8 +106,14 @@ export const CARVE_GUARDS: Record<string, CarveGuard> = {
     scenario:
       'This is a FRESH version-changing ship: the branch has a real code change, VERSION still equals the base version (needs a bump), and CHANGELOG.md needs a new entry. Follow the skill flow for a version-changing ship: run the pre-landing review and prepare the CHANGELOG entry. Produce the ship plan / review report. Do NOT actually commit, push, or open a PR.',
     staticInvariants: {
-      mustStayInSkeleton: [],
-      mustMoveToSection: [],
+      // The PR-title-version invariant MUST stay always-loaded: the v1.54.0.0
+      // carve stranded it in pr-body.md and PRs started landing with bare titles
+      // (CI backstop: test/pr-title-sync-workflow-safety.test.ts).
+      mustStayInSkeleton: ['v$NEW_VERSION', 'gstack-pr-title-rewrite'],
+      // ...while the full create/update procedure stays carved into pr-body.md
+      // (out of the skeleton, present in the union). Asserts BOTH PR paths
+      // survive: the create path and the idempotent update path.
+      mustMoveToSection: ['gh pr create --base', 'gh pr edit --title'],
       // ship is operational (multi-STOP, not a plan review); no single post-STOP gate.
       gateAfterStop: undefined,
     },