Phased plan for the class-balance pass. Unlike the race pass, classes
are *measured* not modeled: combat is one-shot auto-resolved through a
seedable simulateCombatWithRNG, so the harness runs Monte Carlo over the
real engine and reads win rates directly.
Scopes the full matrix (10 classes × 30 subclasses × level checkpoints ×
monster tiers), the two hard policies to de-risk in Phase 0 (equipment
loadout, spell selection), the per-tier win-rate parity rule, and the
tuning levers. Phase 0 spike in progress.
