Phase 6 — JSON API:
- POST /api/v1/auth/login — returns session token
- POST /api/v1/auth/logout
- GET/POST /api/v1/faves — list own faves (paginated), create fave
- GET/PUT/DELETE /api/v1/faves/{id} — get, update, delete fave
- GET /api/v1/tags?q= — search tags
- GET /api/v1/users/{username} — public profile
- GET /api/v1/users/{username}/faves — public faves (paginated)
- GET /api/v1/export/json — export own faves
- POST /api/v1/import — import faves from JSON
All endpoints return JSON. Auth via session cookie (same as web UI).
Privacy-aware: private faves hidden from non-owners.
Respects profile visibility settings.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
