- GET /api/candles accepts ?chartId= with fallback to most recent chart
- GET /api/annotations accepts ?chartId= with fallback to most recent chart
- POST /api/annotations now requires chart_id in request body
- GET /api/export accepts ?chartId= to scope exported annotations
- DELETE /api/annotations supports optional chartId scoping
- CSV upload with papaparse (handles date strings and Unix timestamps)
- Annotations CRUD (GET, POST, DELETE)
- Candles GET endpoint
- Export annotations as CSV