- Add _ensure_indicator_coverage() to verify and backfill after data collection
- Add start_indicator_coverage_monitor() background task for periodic checks
- Configure coverage monitoring with ensure_100_percent_coverage flag
- Set coverage_check_interval_hours (default: 6 hours) for monitoring frequency
- Set backfill_batch_size (default: 200) for efficient backfilling
- Call coverage check after bulk downloads, gap fills, and candle generation
- Start indicator_coverage_monitor task in continuous collection mode
- Log coverage percentages and backfill results for transparency
- Ensure all OHLCV records have complete technical indicator coverage
This integrates the new db.py indicator coverage methods into the main
data collection workflow, ensuring 100% coverage is automatically
maintained across all symbol/interval combinations.
