[JCPetrelli]

Closes #297. Closes #314.

A floor's dog can now be a cat: ⚙️ → Office dog → 🐱 Cat. Same style as the dogs (same toon look, collar, coats), but it moves like a cat.

The model. blender/scripts/build_cat.py builds it on top of build_dog.py (same skin, rig, skinning and export helpers), with a cat's numbers, parts (whiskers, a bell on the collar, a pink nose, tabby stripes) and clips. It keeps the dog contract in blender/README.md: the same 28 bones, sockets, materials and clip names, so the office poses, picks and dresses it up with the dog's code. It's exported as dog-cat.glb (9.3k tris, 0.68 m tall).

The clips, as a cat does them:

• walk: one paw after another (back, front, other back, other front), the back level, the shoulders rolling, the tail up and swaying
• run: a gallop, back legs together, the back arching and stretching
• sit: upright, the tail on the floor and wrapped round the front paws
• sniff: washing, one paw up to the mouth and wiped over the face
• bark: sat up tall meowing at the desk, the tail tip lashing
• lie: a loaf, the paws tucked under the chest
• nap: curled up in a ring, the head tucked in
• wag (petted): the tail straight up with its tip quivering, a head rub, kneading

Every clip passes floor_report (nothing more than 1 cm under the floor). The tail and leg angles for the sit, the loaf and the curl came from a small search over that check.

On the page. features/dog/voice.ts (new) holds what differs between a dog and a cat, so world.ts only asks it and gets shorter (700 → 685 lines). The cat meows instead of barking ("Meow!" bubble) and purrs instead of yipping. Both sounds are made in the browser like the woof, in features/dog/sound.ts. It doesn't pant, it half shuts its eyes when petted, and its nose is pink. The hint bar, name tag, breed toast and settings note say 🐱 and "meowing", "loafing", "curled up under Ada's desk"…

What doesn't change. cat is the last entry in DOG_BREEDS, and it isn't in the dealt list, so no existing floor turns into a cat: it's only ever picked. The server runs the same day for it (follows, naps under desks, runs to workers that need input).

Tested. npm run typecheck, npm test (622 pass: the cat goes through every check in dog-model.test.ts, and the new tests/cat.test.ts covers picking it, saving it, and its voice) and npm run build. Screenshots taken headless from lab/dog.html?breed=cat (each act, a tuxedo coat petted, every breed sitting). I also walked round a local office with it, switching from a dog to the cat in ⚙️ and petting it.