WinRacing V62.0 — Pre-Race Production Readiness Gate

Added:
1. Chairman/audit/wr_chairman_production_readiness_gate_v62_0.php
2. Chairman/api/api_production_readiness_v62.php
3. analysis_chairman_v62_production_readiness.php

Purpose:
- Combine V60 OS health, V61 leakage audit and V53/V54 decision output integrity.
- Block production when critical pre-race safety or output checks fail.
- Remain read-only/advisory-only.

Compatibility:
- No old file removed.
- No database schema change.
- No live-weight change.
- No source decision mutation.
