fix(plex): player marker-skip reset, lang-switch reload, tracks wheel, sidebar badge clamp

- PP1: reset cancelledMarkerRef on item change — a cancelled intro/credits
  auto-skip on one episode suppressed a same-offset marker on the next (auto-skip
  silently dead for the rest of a binge).
- PP2: loadSession no longer depends on the i18n `t` (read via a ref). A
  mid-playback language switch rebuilt loadSession → re-ran the detail effect →
  reloaded the session from the STALE saved resume position, losing live progress.
- PP3: tracks (audio/subtitle) menu now stopPropagation on wheel, like the gear
  menu — scrolling the list no longer changes volume.
- PS1: collapsed PlexSidebar filter badge clamps to "9+" (was a raw count),
  matching the feed Sidebar.

frontend/src/components/PlexPlayer.tsx

@@ -172,6 +172,12 @@ function fmt(t: number): string {
 
 export default function PlexPlayer({ itemId, onClose, queue }: Props) {
   const { t } = useTranslation();
+  // `t` changes identity on a language switch. loadSession only uses it for error strings, so read it
+  // through a ref — keeping it OUT of loadSession's deps. Otherwise a mid-playback language change
+  // rebuilt loadSession → re-ran the detail effect → reloaded the session from the STALE saved resume
+  // position (losing live progress). See the detail effect's deps.
+  const tRef = useRef(t);
+  tRef.current = t;
   const qc = useQueryClient();
   const [id, setId] = useState(itemId);
   const detailQ = useQuery({ queryKey: ["plex-item", id], queryFn: () => api.plexItem(id) });
@@ -284,10 +290,10 @@ export default function PlexPlayer({ itemId, onClose, queue }: Props) {
         // needs full transcoding (a later phase).
         setLoadError(
           e?.status === 501
-            ? t("plex.player.errTranscode")
+            ? tRef.current("plex.player.errTranscode")
             : e?.status === 404
-              ? t("plex.player.errNotFound")
-              : t("plex.player.errGeneric"),
+              ? tRef.current("plex.player.errNotFound")
+              : tRef.current("plex.player.errGeneric"),
         );
         return;
       }
@@ -339,7 +345,7 @@ export default function PlexPlayer({ itemId, onClose, queue }: Props) {
         // A fatal HLS error (e.g. the remux session died / the file became unreadable) would
         // otherwise leave the spinner up forever — surface it instead.
         hls.on(Hls.Events.ERROR, (_e, data) => {
-          if (data.fatal) setLoadError(t("plex.player.errGeneric"));
+          if (data.fatal) setLoadError(tRef.current("plex.player.errGeneric"));
         });
       } else {
         // direct file (or Safari native HLS)
@@ -354,7 +360,7 @@ export default function PlexPlayer({ itemId, onClose, queue }: Props) {
         video.addEventListener("loadedmetadata", onMeta);
       }
     },
-    [id, t],
+    [id], // NOT `t` — see tRef above (a language switch must not rebuild this / reload the session).
   );
 
   // Start playback when the detail arrives (resume from the saved position unless already watched).
@@ -841,6 +847,12 @@ export default function PlexPlayer({ itemId, onClose, queue }: Props) {
   const [skipProgress, setSkipProgress] = useState<number | null>(null);
   skipProgressRef.current = skipProgress;
   const cancelledMarkerRef = useRef<string | null>(null);
+  // Forget a cancelled-skip when the item changes: the ref holds a `${type}-${start_s}` key, and a
+  // marker at the same offset on the NEXT episode would otherwise be suppressed by a cancel made on
+  // the previous one (auto-skip silently dead for the rest of a binge).
+  useEffect(() => {
+    cancelledMarkerRef.current = null;
+  }, [id]);
   // The running countdown interval, so cancelAutoSkip can actually STOP it — clearing skipProgress
   // alone left the interval ticking, which re-set the progress ~100ms later and skipped anyway.
   const skipTimerRef = useRef<number | null>(null);
@@ -1212,6 +1224,7 @@ export default function PlexPlayer({ itemId, onClose, queue }: Props) {
                   <div
                     ref={tracksRef}
                     onClick={(e) => e.stopPropagation()}
+                    onWheel={(e) => e.stopPropagation()}
                     className="glass-menu absolute bottom-full right-0 mb-2 w-56 max-h-[60vh] overflow-auto rounded-xl p-2 text-sm text-white shadow-2xl"
                   >
                     {detail.audio_streams.length > 1 && (