Wire up playback reporting, fix duration flash, hide video from audio mini player

Playback reporting (position sync / resume-on-another-device):
- player_configure_jellyfin now builds a PlaybackReporter sharing the player
  controller's Arc, so Start/Progress/Stopped actually reach Jellyfin on every
  auth path (login/restore/reauth); previously they never did.
- The PlaybackReporterWrapper now shares the same Arc the controller and MPV
  progress loop report through, instead of a dead parallel Option.
- Android position callbacks now emit throttled progress reports (30s/item),
  mirroring the MPV backend.

Duration flash on pause:
- resolveDuration() prefers the live store duration for the already-loaded
  track over the runTimeTicks estimate, so pausing no longer clobbers the
  slider's max to 0 when runTimeTicks is missing.

Video leaking into audio mini player:
- isVideoItem() also checks the backend PlayerMediaItem mediaType
  discriminator, so a video started via player_play_item (no Jellyfin `type`,
  mediaType "video") no longer surfaces in the audio mini player.

Middle-truncation of long media names:
- New truncateMiddle util applied to track/episode/card/mini-player titles so
  distinguishing tails (episode numbers, suffixes) stay visible.

Adds regression tests for the duration and mini-player fixes.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src-tauri/src/player/mod.rs

@@ -165,9 +165,8 @@ impl PlayerController {
         self.jellyfin_client.clone()
     }
 
-    /// Configure the playback reporter for dual sync (local DB + server)
-    /// Will be called from initialization commands after login
-    #[allow(dead_code)]
+    /// Configure the playback reporter for dual sync (local DB + server).
+    /// Called from `player_configure_jellyfin` on login/restore/reauth.
     pub async fn set_playback_reporter(&self, reporter: Option<PlaybackReporter>) {
         let mut reporter_guard = self.playback_reporter.lock().await;
         *reporter_guard = reporter;