fix(enrichment): reject generated titles for superseded content

[johnny4young]

Finding

A generated title can complete after its captured body has been edited. The existing empty-title predicate protects manual titles but permits an annotation for the old body to label the new body.

Correction

• Add optional ContentBoundTitleStoring without removing existing ClipEnriching requirements.
• Apply one guarded GRDB UPDATE: exact full body, still-empty title, live/unarchived/non-sensitive text-backed row and known eligible kind.
• Route generated-title persistence through that capability. A custom store without it skips generated titles rather than falling back to an unsafe write; production GRDB implements it.
• Invoke the title callback only after an accepted write. Rejected results do not dirty upload state or consume the free title taste.
• Inject the annotator for continuation-controlled tests. OCR, embedding behavior, prompts, model choice and manual-title editing are unchanged.
• Document body identity, compatibility and content-equal ABA behavior.

Dependency and exact source

Stacked on #204, base branch fix/content-bound-embeddings at 919acb3.
Exclusive title diff: seven files, 279 additions, six deletions. The parent embedding fix and its one-comma formatter correction are inherited, not repeated independent findings.
Head: 3635b10
Verified local/remote tree: 563196a31ebb4f6e568141507c8a5a21c112c1c9

The earlier draft tree was refreshed to remove the analogous trailing comma in the title test before publication. No assertion or gate was relaxed. Review/integrate #204 before this child; no merge has been performed.

Regression evidence

• Portable extracted-SQL red/green reproduction: the old predicate writes the stale title after a body edit; the guarded predicate rejects it without dirtying, and accepts matching current text.
• Four native persistence tests cover changed body/upload bookkeeping, manual-title precedence, missing/recreated identities and privacy/expiry/kind eligibility.
• A deterministic annotator-barrier test covers changed and unchanged body, accepted callback count and absence of unsafe fallback; no sleeps or model downloads.
• Existing enrichment and ingestion test doubles implement the new guarded capability.
• git diff --check passes, and reconstructed local staged tree equals the published tree.
• This Linux executor lacks Swift/Xcode; make format, make lint and make test are blocked locally, not passed. Exact-head hosted CI 37691238311 supplies native qualification: strict swift-format, SwiftLint and build-warning checks pass; 1,512 package tests in 236 suites pass; production-source coverage is 83.8%, above the unchanged 80% floor. All four new persistence tests and both parameterized annotator-barrier cases pass, along with inherited embedding regressions. StoreKit entitlement tests and both macOS/iOS app builds pass. GitGuardian passes; the non-blocking beta canary was skipped as expected. Scoped exact-head gates are complete; ready for review. No UI layout or interaction flow changed, and the separate full UI workflow was not dispatched.

Limits and reviewer focus

Review the transaction predicate, optional-capability compatibility and callback/upload semantics. Content-equal ABA is valid if the current row remains eligible and untitled; different replacement text is rejected. This does not retroactively repair existing titles or add a new enrichment scheduler.
No UI layout, schema, dependency, threshold, workflow, license, permission, live clipboard, merge, release or deployment changes. No combined qualification of other open repairs is claimed.