feat: add player screen to TV app via compose navigation

- Add PlayerRoute to the Route sealed interface
- Refactor PlayerViewModel to expose loadMedia() for external callers
- Add onPlay() to EpisodeScreenViewModel and MovieScreenViewModel
- Wire play/resume buttons in TV episode and movie screens
- Create TvPlayerScreen with TV-optimized controls: seek bar, playback
  buttons, track selection panels, queue panel, and state cards
- Register PlayerRoute in TvRouteEntryBuilder and TvNavigationModule
- Add media3-ui dependency to app-tv module

core/data/src/main/java/hu/bbara/purefin/core/data/navigation/Route.kt

@@ -21,4 +21,7 @@ sealed interface Route : NavKey {
 
     @Serializable
     data object LoginRoute : Route
+
+    @Serializable
+    data class PlayerRoute(val mediaId: String) : Route
 }

core/player/src/main/java/hu/bbara/purefin/core/player/viewmodel/PlayerViewModel.kt

@@ -124,6 +124,15 @@ class PlayerViewModel @Inject constructor(
 
     private fun loadInitialMedia() {
         val id = mediaId ?: return
+        loadMediaById(id)
+    }
+
+    fun loadMedia(id: String) {
+        if (mediaId != null) return // Already loading from SavedStateHandle
+        loadMediaById(id)
+    }
+
+    private fun loadMediaById(id: String) {
         val uuid = id.toUuidOrNull()
         if (uuid == null) {
             dataErrorMessage = "Invalid media id"