Product decision A (TASK-birth-sky-followup-20260928):
- every generation path writes subject.birthFingerprint (stored-row
fingerprint, same function as the chart page's profileFingerprint);
never into the evidence bundle the model reads
- GET /api/reports/:id compares on the server and returns only
report.coverSubject (subject id or null); legacy reports never get one
- report page shows the night cover above the body, paper cover alone on
the first printed A4 page; silent on any failure, no waiting state
- TS / JSON schema / Python contract accept the optional field
- BLOCKED T5 struck through; DESIGN §17, CHANGELOG, checklist, PROGRESS
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N4f2nya58RoRu4yEmJgRGE
