# Lane A — Engine / Feel

**Owns:** `src/blob/`, `src/course/`, `demos/lane-a.html`, `src/demo/lane-a.ts`.
**Never touches:** `src/contracts.ts`, `src/world.ts`, `src/game.ts`, `src/main.ts`,
`package.json`, other lanes' dirs. New deps are not allowed — three + rapier only.

## Mission
Make moving a blob around feel funny and good. Build the blob controller, the
follow camera, the squash/jiggle, and a greybox course chunk to play in.

## Deliverables
1. `src/blob/createBlob.ts` — implements `Blob` from `src/contracts.ts`:
   - Rapier dynamic ball collider (radius ~0.5) + THREE group with a soft
     white blob mesh (UV sphere is fine — clean UVs matter, Lane B paints them).
   - Movement: WASD/arrows accelerate via impulses/torque, camera-relative;
     Space = jump (grounded check via ray or contact); small air control.
   - Reads `blob.modifiers` EVERY frame and respects: `speedMul`, `jumpMul`,
     `massMul` (scale collider mass), `grip` (0..1, boosts effective friction /
     kill slide), `size` (uniform visual+collider scale).
2. **Feel layer**: squash on landing, stretch on jump, idle wobble — cheap
   sine/spring on mesh scale or vertex shader. It should read as soft-body even
   though physics is a rigid ball. This is the game's comedy engine: overshoot it.
3. `src/blob/camera.ts` — third-person soft-follow camera with lag + slight FOV
   kick at speed.
4. `src/course/greybox.ts` — export `buildGreybox(world)`: a Breakfast Rush
   test chunk from primitives: start plateau, two ramps, a gap jump, a slope,
   a flat "milk river" plane (tagged `surface:water` via userData), open flat
   area (machines land here in integration), finish pad. Big, readable, absurd
   proportions.
5. Demo page `demos/lane-a.html` + `src/demo/lane-a.ts`: boots world, builds
   greybox, spawns blob, plays. Add 3 debug keys: 1/2/3 set
   `modifiers.speedMul=1.6` / `jumpMul=1.5` / `size=1.5` to prove modifier plumbing.

## Acceptance
- `npm run build` passes. Demo runs at 60fps.
- Blob accelerates, jumps, lands with visible squash; wobble reads as soft.
- Debug modifier keys visibly change behavior.
- No edits outside owned paths.

## Contracts (frozen — read `src/contracts.ts` first)
Events you may emit: `blob:landed {impact:number}`, `blob:jumped`.
The world fixed-steps physics at 60Hz; register via `world.addSystem`.