- Add REQUEST_TIMEOUT and RATE_LIMIT_DELAY constants to StockCollector
- Add timeout parameter to all HTTP requests
- Wrap HTTP requests in try-except with proper error handling
- Add _validate_biz_day() method to both collectors
- Add validation for required fields (ticker, name) before insert
- Replace generic Exception with specific exception types in SectorCollector
- Add logging module and logger to both collectors
- Remove unused numpy import from StockCollector
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>