Add 3D object viewers with r3f stack

Add per-class 3D viewers for tiles, tokens, cards, and custom models
using React Three Fiber, drei, and postprocessing. Viewers are
lazy-loaded and registered through the existing viewer registry, with a
shared scene wrapper for lighting, orbit controls, and subtle effects.

Add a CORS-safe /asset proxy route so three.js loaders can fetch
Workshop-hosted textures and models, and extend TTSObject with the
CustomMesh and CustomTile/CustomToken fields the viewers read.

apps/web/package.json

@@ -15,17 +15,22 @@
     "@iconify-json/mdi": "^1.2.3",
     "@iconify/react": "^6.0.2",
     "@iconify/utils": "^3.1.4",
+    "@react-three/drei": "^10.7.8",
+    "@react-three/fiber": "^9.7.0",
+    "@react-three/postprocessing": "^3.0.4",
     "@tts/extract": "workspace:*",
     "@tts/shared": "workspace:*",
     "react": "^19.2.8",
     "react-dom": "^19.2.8",
     "react-router-dom": "^7.18.2",
+    "three": "^0.185.1",
     "zustand": "^5.0.14"
   },
   "devDependencies": {
     "@tailwindcss/vite": "^4.3.3",
     "@types/react": "^19.2.18",
     "@types/react-dom": "^19.2.4",
+    "@types/three": "^0.185.4",
     "@vitejs/plugin-react": "^6.0.5",
     "tailwindcss": "^4.3.3",
     "typescript": "^5.7.2",