New format: WOC (Wowee Open Collision) — binary collision mesh for
custom zone walkability. Magic WOC1 (0x31434F57).
- WoweeCollisionBuilder::fromTerrain() generates collision triangles
from terrain heightmap with slope classification (50 deg threshold)
- Per-triangle flags: walkable (0x01), water (0x02), steep (0x04)
- Respects terrain holes (skips triangles in hole regions)
- Binary save/load with bounds, tile coords, triangle data
- Auto-exported on zone save alongside WOT/WHM/WOM/WOB
- Added to content pack validation (score now 0-7)
- FORMAT_SPEC.md v1.1 updated with WOC binary layout
- 19 new test assertions: flat terrain generation (32k tris all
walkable), save/load round-trip, hole skipping
- 328 total assertions across 84 test cases
