feat(photo-library): Lightroom-inspired catalog and non-destructive adjust

Summary

Adds src/photo-library/ — ratings, flags, filters, CSS non-destructive preview. Catalog workflow (not a Photo Studio clone). Amplify/README + icons.

DOCUMENTED vs LIVE

See src/photo-library/README.md — honest comparison; no fabricated LIVE access.

Test plan

• cd src/photo-library && npm ci && npm test && npm run build (4 tests)
• Smoke the UI