Features CSV contains rows with two date formats:
- Old rows: '2003-02-01 00:00:00' (with time)
- New rows: '2026-04-01' (date only)
pd.to_datetime() infers format from first rows then rejects the
date-only values with ValueError. Fix: format='mixed' across all
pd.to_datetime() calls in live_data_fetcher, portfolio_engine,
and explainability_engine.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Comprehensive date/error handling fixes across services
FastAPI + ML backend with regime detection, SHAP explainability,
stress testing, and live market data scheduler.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>