Instrument every API endpoint with Server-Timing headers so sub-operation
durations are visible in browser DevTools Network tab. Also adds Grafana
dashboard panels for per-endpoint latency comparison (p50/p95 timeseries
and p95 ranking bar gauge).
- ListingDecision model with unique constraint on (user_id, listing_id, listing_type)
- Alembic migration for listingdecision table
- DecisionRepository with dialect-aware upsert (MySQL/SQLite)
- DecisionService with input validation
- Decision API routes: PUT/GET/DELETE on /api/decisions
- GET /api/listing/{id}/detail endpoint extracting full property info from additional_info
- Add listing ID to GeoJSON feature properties
- Decision filtering on GeoJSON stream endpoint (decision_filter param)
PUT /api/decisions/{listing_id} to set decision,
GET /api/decisions to list all user decisions,
DELETE /api/decisions/{listing_id} to remove a decision.
All 6 API route tests pass.
