feat: intraday hourly price bars via Polygon range endpoint

- New 'intraday_bars' endpoint in PolygonMarketAdapter: fetches hourly
  bars for today using range_bars URL with timespan=hour, sort=asc
- Scheduler expands intraday_bars global source into per-ticker jobs
  for all active companies (every 15 minutes via polling_interval)
- Migration 025 inserts the intraday source with 900s cadence
- Frontend price matching uses closest-timestamp instead of date-string
  matching, with 2h tolerance for intraday and 36h for daily windows
- Bumped market price fetch limit to 200 for intraday granularity

infra/migrations/025_intraday_market_source.sql

@@ -0,0 +1,15 @@
+-- Add intraday market data source (hourly bars via Polygon range endpoint).
+-- The scheduler expands this into per-ticker jobs every 15 minutes.
+
+INSERT INTO sources (source_type, source_name, config, active, company_id)
+SELECT
+    'market_api',
+    'Polygon Intraday Hourly',
+    '{"endpoint": "intraday_bars", "provider": "polygon", "timespan": "hour", "multiplier": 1, "adjusted": true, "polling_interval_seconds": 900}'::jsonb,
+    true,
+    NULL
+WHERE NOT EXISTS (
+    SELECT 1 FROM sources
+    WHERE source_type = 'market_api'
+      AND config->>'endpoint' = 'intraday_bars'
+);