Phase 0: drivable car with persistent wear

Vite + TypeScript + three.js + Rapier raycast vehicle, fixed 60 Hz step.

Flat plate, seeded obstacle scatter, chase camera, debug HUD. Car condition
(engine/tires/chassis) degrades permanently and is derived into handling
numbers, so decline is felt through the wheel rather than read off a meter.

src/sim/ is kept free of three.js and Rapier imports — the later heat, region
and front-line systems all live there, and staying engine-free is what makes
them unit-testable without a browser.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,7 @@
+node_modules/
+dist/
+.DS_Store
+*.local
+
+# local Claude Code settings
+.claude/settings.local.json