feat(core): add anime.js runtime adapter (#569)

## Summary
- Adds a `RuntimeDeterministicAdapter` for anime.js v4+ alongside existing Lottie, Three.js, WAAPI, and CSS adapters
- Enables frame-accurate rendering of anime.js animations — the adapter converts seek time (seconds) to milliseconds and calls `.seek(timeMs)` on registered instances
- Auto-discovers running instances via `anime.running`; compositions can also register manually via `window.__hfAnime`

## Usage in compositions

```html
<script src="https://cdn.jsdelivr.net/npm/animejs@4.0.2/lib/anime.iife.min.js"></script>
<script>
  const anim = anime({
    targets: '.box',
    translateX: 250,
    rotate: '1turn',
    duration: 2000,
    autoplay: false,
  });
  window.__hfAnime = window.__hfAnime || [];
  window.__hfAnime.push(anim);
</script>
```

## Files changed
- `packages/core/src/runtime/adapters/animejs.ts` — adapter implementation
- `packages/core/src/runtime/adapters/animejs.test.ts` — 15 unit tests
- `packages/core/src/runtime/init.ts` — register adapter in runtime init
- `packages/core/src/runtime/window.d.ts` — add `anime` and `__hfAnime` globals

## Test plan
- [x] All 15 unit tests pass (`bun run --cwd packages/core test -- --run adapters/animejs`)
- [x] Build passes (`bun run build`)
- [x] Pre-commit hooks pass (lint, format, typecheck, commitlint)
- [x] Manual test: render a composition using anime.js animations

packages/core/src/runtime/window.d.ts

@@ -43,6 +43,24 @@ declare global {
       };
     };
     THREE?: ThreeLike;
+    /**
+     * Global anime.js instance (set by including the anime.iife.min.js script).
+     * The adapter uses `anime.running` for auto-discovery.
+     */
+    anime?: {
+      (params: unknown): unknown;
+      timeline?: (params?: unknown) => unknown;
+      running: unknown[];
+    };
+    /**
+     * anime.js instances registered by compositions.
+     * The adapter seeks all instances when the player is seeked.
+     *
+     * Push your animation or timeline instance here:
+     *   window.__hfAnime = window.__hfAnime || [];
+     *   window.__hfAnime.push(anim);
+     */
+    __hfAnime?: unknown[];
     /**
      * Global lottie-web instance (set by including the lottie.min.js script).
      * The adapter uses `lottie.getRegisteredAnimations()` for auto-discovery.