WinRacing V52.8 Long-term Performance Analytics

- Added multi-race-date snapshot analytics.
- Added rolling Top3, FP, FN, MAE and learning-confidence trends.
- Added long-term Pattern and Race DNA profile ranking.
- Added long-term Error Root Cause priority ranking.
- Added Memory Strength and Simulation Impact trend metrics.
- Added Dashboard and API output for long_term_performance_analytics.
- Advisory only. No V44-V51 production weight, score or decision changed.
- No database schema mutation.