feat: initialize Video.js 10 monorepo with core architecture

- Set up monorepo structure with core, HTML, React, and React Native packages
- Add TypeScript configuration with project references
- Create foundational packages: media-store, playback-engine, media, icons
- Implement platform-specific packages for HTML, React, and React Native
- Add comprehensive documentation and development tooling
- Include CLAUDE.md with development guidelines and conventional commits

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

packages/core/playback-engine/src/index.ts

@@ -0,0 +1,83 @@
+export interface MediaSource {
+  src: string;
+  type: string;
+}
+
+export interface PlaybackEngineOptions {
+  autoplay?: boolean;
+  preload?: 'none' | 'metadata' | 'auto';
+}
+
+export abstract class PlaybackEngine {
+  protected element: HTMLMediaElement | null = null;
+  protected options: PlaybackEngineOptions;
+
+  constructor(options: PlaybackEngineOptions = {}) {
+    this.options = options;
+  }
+
+  abstract attach(element: HTMLMediaElement): void;
+  abstract detach(): void;
+  abstract load(source: MediaSource): Promise<void>;
+  abstract play(): Promise<void>;
+  abstract pause(): void;
+  abstract seekTo(time: number): void;
+
+  getElement(): HTMLMediaElement | null {
+    return this.element;
+  }
+}
+
+export class NativePlaybackEngine extends PlaybackEngine {
+  attach(element: HTMLMediaElement): void {
+    this.element = element;
+  }
+
+  detach(): void {
+    this.element = null;
+  }
+
+  async load(source: MediaSource): Promise<void> {
+    if (!this.element) {
+      throw new Error('No media element attached');
+    }
+    
+    this.element.src = source.src;
+    await new Promise((resolve, reject) => {
+      const onLoad = () => {
+        this.element!.removeEventListener('loadedmetadata', onLoad);
+        this.element!.removeEventListener('error', onError);
+        resolve(void 0);
+      };
+      const onError = () => {
+        this.element!.removeEventListener('loadedmetadata', onLoad);
+        this.element!.removeEventListener('error', onError);
+        reject(new Error('Failed to load media'));
+      };
+      
+      this.element.addEventListener('loadedmetadata', onLoad);
+      this.element.addEventListener('error', onError);
+    });
+  }
+
+  async play(): Promise<void> {
+    if (!this.element) {
+      throw new Error('No media element attached');
+    }
+    await this.element.play();
+  }
+
+  pause(): void {
+    if (!this.element) {
+      throw new Error('No media element attached');
+    }
+    this.element.pause();
+  }
+
+  seekTo(time: number): void {
+    if (!this.element) {
+      throw new Error('No media element attached');
+    }
+    this.element.currentTime = time;
+  }
+}