feat: replace mpv with hls.js HTML5 video player (v0.4.0)

- Remove mpvController.ts and hlsTrimmer.ts entirely
  - Rewrite PlaybackService: streamlink --stream-url → HLS-URL → IPC event playback:hls-url
  - Add VideoPlayer.tsx (hls.js <video> wrapper, forwardRef with seek/seekTo/pause/play/stop/getCurrentTime)
  - Integrate VideoPlayer into ChannelScreen with direct videoRef calls (no IPC roundtrip for seek/pause)
  - Add global AppShell playback overlay for direct stream start (A-button in Browse/Category/StreamList)
  - Propagate onStartLive callback through BrowseScreen, CategoryScreen, StreamListScreen
  - Add CORS bypass for Twitch CDN (webRequest.onBeforeSendHeaders) and autoplay-policy switch
  - Update CSP: add media-src 'self' blob: for hls.js MediaSource API
  - Open chapter panel without stopping playback (pause + resume instead of stop/restart)
  - Drop IPC channels: seek, seekTo, resume, togglePause, getCurrentPosition, onTimeUpdate
  - Add IPC channel: playback:hls-url event with HlsUrlPayload

package.json

@@ -1,6 +1,6 @@
 {
   "name": "twitch4steamdeck",
-  "version": "0.3.4",
+  "version": "0.4.0",
   "description": "Twitch-Client für das Steam Deck (Live & VOD, Big-Screen-UI)",
   "main": "out/main/index.js",
   "author": "twitch4steamdeck",
@@ -17,6 +17,7 @@
   },
   "dependencies": {
     "better-sqlite3": "^12.8.0",
+    "hls.js": "^1.6.16",
     "qrcode": "^1.5.4",
     "react": "^18.3.1",
     "react-dom": "^18.3.1"