WinRacing V52.5 Race DNA Learning Engine

- Added per-race Race DNA Signature.
- Added DNA type: STRONG, BALANCED, VOLATILE, DANGER.
- Added DNA recommendation: PROMOTE, HOLD, WATCH, AVOID.
- Added DNA volatility, Bayesian posterior Top3 rate, lift and stability.
- Added Race DNA Profile Library and Dashboard/API output.
- Advisory only: no V44-V51 weights or decisions are modified.
- No database schema changes.