feat: allow clip animation + ship <hyperframes-player> web component (#209)

## Summary

Two independent initiatives that improve agent DX and expand HyperFrames' reach.

### Initiative 1: Fix the Clip Animation Footgun

- `gsap_animates_clip_element` lint rule now uses smart detection — only errors when GSAP animates `visibility` or `display` on a clip element
- All other properties (opacity, transform, x, y, scale, etc.) are allowed silently
- This was the #1 agent failure in QA (10/10 agents hit it on v0.2.1)

### Initiative 2: `<hyperframes-player>` Web Component

- New `@hyperframes/player` package — zero dependencies, 3.3KB gzipped
- Iframe-based web component with Shadow DOM for perfect isolation
- Video-like API: `play()`, `pause()`, `seek()`, `currentTime`, `duration`, events
- Controls overlay with play/pause, scrubber (mouse + touch), time display, auto-hide
- Full docs page at `docs/packages/player.mdx`

## Before / After

### Clip animation lint

**Before (10/10 agents hit this):**

```
✗ gsap_animates_clip_element: GSAP animation targets a clip element.
  Selector "#title" resolves to element <div id="title" class="clip">.
  The framework manages clip visibility — animate an inner wrapper instead.
  Fix: Wrap content in a child <div> and target that with GSAP.
```

**After (only errors on actual conflicts):**

```
# This passes lint — no error:
tl.from("#title", { opacity: 0, y: -50, scale: 0.8 }, 0);

# This still errors — actual conflict with runtime:
tl.to("#title", { visibility: "hidden" }, 3);
✗ gsap_animates_clip_element: GSAP animation sets visibility on a clip element.
  Fix: Remove the visibility/display tween. Use opacity for fade effects.
```

### Embeddable player

**Before:** No way to embed a composition in a web page.
**After:**

```html
<script src="https://cdn.jsdelivr.net/npm/@hyperframes/player"></script>
<hyperframes-player src="./composition/index.html" controls></hyperframes-player>
```

```js
const player = document.querySelector('hyperframes-player');
player.play();
player.pause();
player.seek(2.5);
player.addEventListener('ready', (e) => console.log('Duration:', e.detail.duration));
```

## Test plan

- [x] 427 core tests pass (20 GSAP lint tests with smart detection)
- [x] 7 player tests pass (formatTime + element registration)
- [x] TypeScript compiles cleanly (core + player)
- [x] Lint: GSAP animating clip with safe props → 0 errors
- [x] Lint: GSAP animating clip with `visibility` → 1 error (correct)
- [x] Player builds to 3.3KB gzipped ESM
- [x] Lockfile updated for CI
- [x] Docs page added at `docs/packages/player.mdx`

packages/player/src/styles.ts

@@ -0,0 +1,114 @@
+export const PLAYER_STYLES = /* css */ `
+  :host {
+    display: block;
+    position: relative;
+    overflow: hidden;
+    background: #000;
+    contain: layout style;
+  }
+
+  .hfp-container {
+    position: absolute;
+    inset: 0;
+    overflow: hidden;
+    pointer-events: none;
+  }
+
+
+  .hfp-iframe {
+    position: absolute;
+    top: 50%;
+    left: 50%;
+    border: none;
+    pointer-events: none;
+  }
+
+  .hfp-poster {
+    position: absolute;
+    inset: 0;
+    object-fit: contain;
+    z-index: 1;
+    pointer-events: none;
+  }
+
+  .hfp-controls {
+    position: absolute;
+    bottom: 0;
+    left: 0;
+    right: 0;
+    display: flex;
+    align-items: center;
+    gap: 12px;
+    padding: 8px 16px;
+    background: linear-gradient(transparent, rgba(0, 0, 0, 0.7));
+    color: #fff;
+    font-family: system-ui, -apple-system, sans-serif;
+    font-size: 13px;
+    z-index: 10;
+    pointer-events: auto;
+    opacity: 1;
+    transition: opacity 0.3s ease;
+    user-select: none;
+  }
+
+  .hfp-controls.hfp-hidden {
+    opacity: 0;
+    pointer-events: none;
+  }
+
+  .hfp-play-btn {
+    background: none;
+    border: none;
+    color: #fff;
+    cursor: pointer;
+    padding: 8px;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    width: 40px;
+    height: 40px;
+    flex-shrink: 0;
+    z-index: 10;
+  }
+
+  .hfp-play-btn:hover {
+    opacity: 0.8;
+  }
+
+  .hfp-play-btn svg,
+  .hfp-play-btn svg * {
+    pointer-events: none;
+  }
+
+  .hfp-scrubber {
+    flex: 1;
+    height: 4px;
+    background: rgba(255, 255, 255, 0.3);
+    border-radius: 2px;
+    cursor: pointer;
+    position: relative;
+  }
+
+  .hfp-scrubber:hover {
+    height: 6px;
+  }
+
+  .hfp-progress {
+    position: absolute;
+    top: 0;
+    left: 0;
+    height: 100%;
+    background: #fff;
+    border-radius: 2px;
+    pointer-events: none;
+  }
+
+  .hfp-time {
+    flex-shrink: 0;
+    font-variant-numeric: tabular-nums;
+    opacity: 0.9;
+  }
+`;
+
+export const PLAY_ICON = `<svg width="24" height="24" viewBox="0 0 18 18" fill="currentColor"><polygon points="4,2 16,9 4,16"/></svg>`;
+export const PAUSE_ICON = `<svg width="24" height="24" viewBox="0 0 18 18" fill="currentColor"><rect x="3" y="2" width="4" height="14"/><rect x="11" y="2" width="4" height="14"/></svg>`;