feat: Add daily baseline payload logic (12:01 AM - 3:00 AM window)

- Replace saveRawPayload with saveDailyBaseline in all handlers
- Full payloads only saved once per day per store during window
- Inventory snapshots still saved every crawl (lightweight tracking)
- Add last_baseline_at column to dispensaries table
- Show baseline status in Per-Store Schedules dashboard
- Display baseline window info (12:01 AM - 3:00 AM) in UI

Reduces storage ~95% for high-frequency stores while maintaining
full audit capability via daily baselines.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/migrations/120_daily_baseline_tracking.sql

@@ -0,0 +1,13 @@
+-- Migration 120: Daily baseline tracking
+-- Track when each store's daily baseline payload was last saved
+-- Part of Real-Time Inventory Tracking feature
+
+-- Add column to track last baseline save time
+ALTER TABLE dispensaries ADD COLUMN IF NOT EXISTS last_baseline_at TIMESTAMPTZ DEFAULT NULL;
+
+-- Index for finding stores that need baselines
+CREATE INDEX IF NOT EXISTS idx_dispensaries_baseline ON dispensaries(last_baseline_at)
+WHERE crawl_enabled = TRUE;
+
+-- Comment
+COMMENT ON COLUMN dispensaries.last_baseline_at IS 'Timestamp of last daily baseline payload save. Baselines saved once per day between 12:01 AM - 3:00 AM.';