- POST /api/station/backfill: pages backward through Ambient's historical API
at 1 req/sec, deduplicates against existing JSONL records, writes to daily files
- GET /api/station/backfill/status: polls live progress (days done, readings inserted)
- Dashboard settings panel: day-range selector (7d/30d/90d/180d/1y), Import button,
progress bar with live count; auto-reloads charts when complete
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>