Initial release: game-studio plugin for Claude Code

Repackaged from OpenAI's game-studio Codex plugin (MIT) for Claude Code.

Changes from upstream:
- Added .claude-plugin/plugin.json (Claude Code plugin manifest)
- Removed .codex-plugin/plugin.json (Codex CLI specific)
- Removed skills/*/agents/openai.yaml (Codex CLI specific)
- Added scripts/requirements.txt (Pillow dependency for sprite-pipeline)
- Added Chinese README with installation guide

references/threejs-vanilla-starter.md

@@ -0,0 +1,58 @@
+# Three.js Vanilla Starter
+
+Use this as the smallest canonical starting point for a plain TypeScript or Vite Three.js app.
+
+## Files
+
+```text
+src/
+  main.ts
+```
+
+## `src/main.ts`
+
+```ts
+import * as THREE from "three";
+
+const scene = new THREE.Scene();
+scene.background = new THREE.Color("#101418");
+
+const camera = new THREE.PerspectiveCamera(60, window.innerWidth / window.innerHeight, 0.1, 200);
+camera.position.set(0, 1.5, 4);
+
+const renderer = new THREE.WebGLRenderer({ antialias: true });
+renderer.setPixelRatio(Math.min(window.devicePixelRatio, 2));
+renderer.setSize(window.innerWidth, window.innerHeight);
+document.body.appendChild(renderer.domElement);
+
+scene.add(new THREE.AmbientLight(0xffffff, 0.7));
+const light = new THREE.DirectionalLight(0xffffff, 1.2);
+light.position.set(4, 6, 3);
+scene.add(light);
+
+const mesh = new THREE.Mesh(
+  new THREE.BoxGeometry(1, 1, 1),
+  new THREE.MeshStandardMaterial({ color: "#3dd9b8" }),
+);
+scene.add(mesh);
+
+window.addEventListener("resize", () => {
+  camera.aspect = window.innerWidth / window.innerHeight;
+  camera.updateProjectionMatrix();
+  renderer.setSize(window.innerWidth, window.innerHeight);
+});
+
+renderer.setAnimationLoop(() => {
+  mesh.rotation.y += 0.01;
+  renderer.render(scene, camera);
+});
+```
+
+## Notes
+
+- Start here for direct loop and renderer control.
+- If the scaffold needs UI, start with one compact objective chip and one transient controls hint rather than multiple permanent cards.
+- Keep notes, codex, maps, and settings behind on-demand surfaces. The starter scene should stay readable while moving the camera.
+- Add GLB loading with `gltf-loading-starter.md`.
+- Add physics sync with `rapier-integration-starter.md`.
+- Use `three-hud-layout-patterns.md` for low-chrome 3D overlay defaults.