refactor: remove duplicate VOD start and chapter panel helpers

handleWatchVodFromChapter was identical to handleWatchVod except for an
optional startSeconds argument that the bridge already supports. Merged
into a single function with startSeconds?: number.

openChapterPanel was a wrapper around showChapterPanel whose two branches
both executed the same code. Removed the wrapper; call sites now call
showChapterPanel directly.

Also removes stale mpv references from CLAUDE.md that were superseded by
the hls.js migration commit.

CLAUDE.md

@@ -84,8 +84,6 @@ bash flatpak/build-flatpak.sh
 ```
 Das Skript: prüft deps → npm-Build → Python-Deps generieren → Streamlink-Tarballs hashen → `flatpak-builder` → SCP zum Steam Deck.
 
-> **Hinweis:** Das Flatpak-Manifest (`flatpak/tv.twitch4steamdeck.App.yml`) enthält noch mpv als Dependency — muss bereinigt werden, sobald der hls.js-Ansatz auf dem Steam Deck getestet und bestätigt ist.
-
 ---
 
 ## Codebase-Struktur
@@ -154,11 +152,10 @@ scripts/
   test-playback-pipeline.mjs  — Standalone-Test: streamlink → HLS-URL → Manifest → Segment (node scripts/test-playback-pipeline.mjs twitch.tv/<kanal>)
 
 flatpak/
-  tv.twitch4steamdeck.App.yml — Flatpak-Manifest (Streamlink, alle Native-Deps; mpv-Einträge noch zu bereinigen)
+  tv.twitch4steamdeck.App.yml — Flatpak-Manifest (Streamlink, alle Native-Deps)
   build-flatpak.sh            — 6-Schritt Build-Pipeline (WSL2)
   twitch4steamdeck.sh         — Launcher mit zypak-wrapper
   tv.twitch4steamdeck.App.desktop
-  patches/mpv-ffmpeg7-avio-const.patch  — (obsolet nach mpv-Entfernung)
 ```
 
 ---
@@ -259,7 +256,7 @@ Wenn der User während der Wiedergabe das Kapitel-Panel öffnet (Y-Taste), läuf
 
 | Problem | Status | Details |
 |---|---|---|
-| hls.js Performance auf Steam Deck | Ungetestet | Chromiums VA-API Hardware-Decode sollte ausreichen. Falls Dropped Frames bei 1080p60 → Qualitäts-Button im Overlay nutzen (720p60 wählen) oder mpv-Fallback evaluieren. |
+| hls.js Performance auf Steam Deck | Ungetestet | Chromiums VA-API Hardware-Decode sollte ausreichen. Falls Dropped Frames bei 1080p60 → Qualitäts-Button im Overlay nutzen (720p60 wählen). |
 | Twitch Live-Stream URL-Expiry | Unkritisch | `streamlink --stream-url` Token in URL kann ablaufen. hls.js handelt Playlist-Refresh automatisch; bei Verbindungsabbruch muss neu gestartet werden. |
 | Ad-Bypass | Nicht implementiert | `--twitch-disable-ads` von Streamlink deprecated. Post-MVP. |
 | Flaggen-Emojis auf Windows | Nur Rechtecke | Unicode Regional Indicators brauchen Noto Color Emoji (Linux). Im Dev-Mode ignorieren. |

src/renderer/src/screens/ChannelScreen.tsx

@@ -157,7 +157,7 @@ export default function ChannelScreen({ channel, onBack }: Props): JSX.Element {
             setFocusRegion('hero')
           } else {
             if (chapter) {
-              void handleWatchVodFromChapter(vod, chapter.positionSeconds)
+              void handleWatchVod(vod, chapter.positionSeconds)
             } else {
               void handleWatchVod(vod)
               setChapterPanelVod(null)
@@ -229,7 +229,7 @@ export default function ChannelScreen({ channel, onBack }: Props): JSX.Element {
           case 'y': {
             e.preventDefault()
             const vod = currentVod ?? vods[shelfIndex]
-            if (vod) openChapterPanel(vod, true)
+            if (vod) showChapterPanel(vod)
             break
           }
           case 'x':
@@ -273,7 +273,7 @@ export default function ChannelScreen({ channel, onBack }: Props): JSX.Element {
         if (e.key === 'y') {
           e.preventDefault()
           const vod = vods[shelfIndex]
-          if (vod) openChapterPanel(vod, false)
+          if (vod) showChapterPanel(vod)
         } else if (e.key === 'ArrowLeft') {
           e.preventDefault()
           setShelfIndex((i) => Math.max(0, i - 1))
@@ -413,54 +413,7 @@ export default function ChannelScreen({ channel, onBack }: Props): JSX.Element {
       .catch(() => setAvailableQualities([]))
   }
 
-  const handleWatchVod = async (vod: VodInfo): Promise<void> => {
+  const handleWatchVod = async (vod: VodInfo, startSeconds?: number): Promise<void> => {
-    setPlayState('starting')
-    setErrorMsg('')
-    setFocusRegion('hero')
-    setChapterPanelVod(null)
-    setCurrentVod(vod)
-    setPendingChapterVod(null)
-    setVodChaptersLoaded(false)
-    setAvailableQualities(undefined)
-    setCurrentQuality('best')
-    setQualityPanelOpen(false)
-    void loadChapters(vod.id)
-      .then((loaded) => { setChapters(loaded); setVodChaptersLoaded(true) })
-      .catch(() => { setVodChaptersLoaded(true) })
-    try {
-      await window.t4sd.playback.startVod(
-        vod.id,
-        channel.broadcasterLogin,
-        vod.title,
-        vod.durationSeconds
-      )
-    } catch (e) {
-      setPlayState('error')
-      setErrorMsg(String(e))
-      return
-    }
-    window.t4sd.playback.getQualities(`twitch.tv/videos/${vod.id}`)
-      .then((qs) => setAvailableQualities(qs.length > 0 ? qs : []))
-      .catch(() => setAvailableQualities([]))
-  }
-
-  const openChapterPanel = (vod: VodInfo, duringPlayback: boolean): void => {
-    if (duringPlayback) {
-      setChapterPanelVod(vod)
-      setChapters([])
-      setChapterIndex(0)
-      setChaptersLoading(true)
-      setFocusRegion('chapters')
-      void loadChapters(vod.id)
-        .then((loaded) => setChapters(loaded))
-        .catch(() => {})
-        .finally(() => setChaptersLoading(false))
-      return
-    }
-    showChapterPanel(vod)
-  }
-
-  const handleWatchVodFromChapter = async (vod: VodInfo, startSeconds: number): Promise<void> => {
     setPlayState('starting')
     setErrorMsg('')
     setFocusRegion('hero')
@@ -815,7 +768,7 @@ export default function ChannelScreen({ channel, onBack }: Props): JSX.Element {
           }}
           onChangeQuality={(q) => void handleQualityChange(q)}
           onOpenChapters={!isLivePlayback && currentVod
-            ? () => openChapterPanel(currentVod, true)
+            ? () => showChapterPanel(currentVod)
             : undefined}
           onTogglePause={() => {
             if (playState === 'playing') {