feat(android): TrackActions hidden-state reacts to SSE (audit v3 Bug-9/§4.12)

TrackActionsViewModel fetched the hidden-track snapshot only at init
and after local flag/unflag, so a hide/unhide from another device
left the sheet's Hide/Unhide label stale until the VM was recreated.
Now it subscribes to EventsStream and refreshes on any quarantine.*
event (flagged / unflagged / resolved / file_deleted /
deleted_via_lidarr).

Also routed the radio / append-to-playlist / hide / unhide failure
snackbars through ErrorCopy.fromThrowable instead of raw it.message,
keeping the action-context prefix.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

android/app/src/main/java/com/fabledsword/minstrel/shared/widgets/trackactions/TrackActionsViewModel.kt

@@ -2,6 +2,8 @@ package com.fabledsword.minstrel.shared.widgets.trackactions
 
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
+import com.fabledsword.minstrel.api.ErrorCopy
+import com.fabledsword.minstrel.events.EventsStream
 import com.fabledsword.minstrel.likes.data.LikesRepository
 import com.fabledsword.minstrel.models.TrackRef
 import com.fabledsword.minstrel.player.PlayerController
@@ -15,6 +17,7 @@ import kotlinx.coroutines.flow.SharedFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asSharedFlow
 import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.filter
 import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.launch
 import javax.inject.Inject
@@ -31,9 +34,10 @@ import javax.inject.Inject
  * Hidden-state observation: [QuarantineRepository] doesn't yet expose
  * a Flow for the caller's quarantine list (no Room cache; see the
  * repository's class comment), so this VM holds its own snapshot of
- * the hidden track-id set. Refreshed on init and after every flag /
- * unflag action so the sheet reflects the current state next time
- * it opens for the same track.
+ * the hidden track-id set. Refreshed on init, after every flag /
+ * unflag action, AND on any `quarantine.*` SSE event so a hide/unhide
+ * from another device updates the sheet's Hide/Unhide label without
+ * a manual reload.
  */
 @HiltViewModel
 class TrackActionsViewModel @Inject constructor(
@@ -41,6 +45,7 @@ class TrackActionsViewModel @Inject constructor(
     private val quarantine: QuarantineRepository,
     private val player: PlayerController,
     private val playlists: PlaylistsRepository,
+    private val eventsStream: EventsStream,
 ) : ViewModel() {
 
     private val messages = MutableSharedFlow<String>(extraBufferCapacity = 4)
@@ -51,6 +56,11 @@ class TrackActionsViewModel @Inject constructor(
 
     init {
         refreshHidden()
+        viewModelScope.launch {
+            eventsStream.events
+                .filter { it.kind.startsWith("quarantine.") }
+                .collect { refreshHidden() }
+        }
     }
 
     fun isLikedFlow(trackId: String): Flow<Boolean> =
@@ -84,7 +94,9 @@ class TrackActionsViewModel @Inject constructor(
     fun startRadio(trackId: String) {
         viewModelScope.launch {
             runCatching { player.startRadio(trackId) }
-                .onFailure { messages.tryEmit("Couldn't start radio: ${it.message ?: "unknown error"}") }
+                .onFailure {
+                    messages.tryEmit("Couldn't start radio: ${ErrorCopy.fromThrowable(it)}")
+                }
         }
     }
 
@@ -92,7 +104,9 @@ class TrackActionsViewModel @Inject constructor(
         viewModelScope.launch {
             runCatching { playlists.appendTrack(playlistId, trackId) }
                 .onSuccess { messages.tryEmit("Added to playlist") }
-                .onFailure { messages.tryEmit("Couldn't add to playlist: ${it.message ?: "unknown error"}") }
+                .onFailure {
+                    messages.tryEmit("Couldn't add to playlist: ${ErrorCopy.fromThrowable(it)}")
+                }
         }
     }
 
@@ -100,7 +114,7 @@ class TrackActionsViewModel @Inject constructor(
         viewModelScope.launch {
             runCatching { quarantine.flag(track.id, reason, notes) }
                 .onSuccess { refreshHidden() }
-                .onFailure { messages.tryEmit("Couldn't hide: ${it.message ?: "unknown error"}") }
+                .onFailure { messages.tryEmit("Couldn't hide: ${ErrorCopy.fromThrowable(it)}") }
         }
     }
 
@@ -108,7 +122,7 @@ class TrackActionsViewModel @Inject constructor(
         viewModelScope.launch {
             runCatching { quarantine.unflag(trackId) }
                 .onSuccess { refreshHidden() }
-                .onFailure { messages.tryEmit("Couldn't unhide: ${it.message ?: "unknown error"}") }
+                .onFailure { messages.tryEmit("Couldn't unhide: ${ErrorCopy.fromThrowable(it)}") }
         }
     }