Add map evolution pipeline (cmd/acb-map-evolver)
Phase 9 implementation: Map Evolution (§14.6)
- Parent selection weighted by engagement × vote multiplier
- Crossover with sector-based wall inheritance
- Symmetry-preserving mutation (wall flips, energy node shifts)
- Validation: connectivity, wall density bounds, energy node access
- Smoke test validation (simplified: connectivity + energy count checks)
- PostgreSQL maps, map_votes, map_fairness tables for lifecycle management
- Maps stored with status: active, probation, retired, classic
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>