Rapier 2D (@dimforge/rapier2d-compat 0.20) comes in as the physics engine: the editor loads it once in the background right after opening a project from its own chunk, so the main bundle grows by 0.19 KB gzip and the first frame does not wait; loadPhysics, physicsStatus and the 100 px = 1 m conversion live in src/runtime/physics/engine.ts, __gm.physics() reports the state, unit tests pin free fall and a box resting on a box, and e2e module 41 pins that Rapier is ready from its own chunk without console noise (#145)

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

README.md

@@ -38,7 +38,7 @@ npm run build        # writes dist/ and regenerates index.html; the folder is wh
 The browser suite and the three example games need a machine with a GPU:
 
 ```bash
-node tools/seed-e2e.mjs && node tools/e2e.mjs      # the editor, 1042 checks (GM_STEPS=20 for one step)
+node tools/seed-e2e.mjs && node tools/e2e.mjs      # the editor, 1045 checks (GM_STEPS=20 for one step)
 node tools/seed-jumprun.mjs && node tools/smoke-jumprun.mjs
 node tools/seed-tetris.mjs && node tools/smoke-tetris.mjs
 node tools/seed-actor.mjs && node tools/smoke-actor.mjs