- Add check_indicator_coverage() to detect OHLCV records missing indicators
- Add get_ohlcv_missing_indicators() to identify specific gaps
- Add backfill_missing_indicators() to fill missing indicator data
- Add get_ohlcv_data_range() helper for fetching historical data
- Add get_all_indicator_coverage_status() for system-wide monitoring
- Define REQUIRED_INDICATORS constant with all 16 required indicators
- Process backfills in configurable batches to manage memory
- Calculate indicators using existing utils.calculate_technical_indicators()
- Track coverage statistics before/after backfill operations
- Support for automated indicator completeness verification
This ensures every crypto_ohlcv record has all 16 technical indicators
(adx_14, atr_14, bb_lower, bb_middle, bb_upper, ema_12, ema_26,
macd_histogram, macd_line, macd_signal, rsi_14, sma_20, sma_200,
sma_50, stoch_d, stoch_k) calculated and stored
