fix(android): key UiState Crossfades on state::class to stop refresh flicker

Pull-to-refresh produced a strong full-screen fade on Library
(both tabs) and the Album / Artist / Playlist detail screens
because their Crossfades were keyed on the entire state value.
A refresh emits a fresh UiState.Success with a NEW data instance
(same kind, different content) so Crossfade animated old grid →
new grid even though both are the same Success branch — the
visible result was a flash that read as "broken/heavy."

HomeScreen already keys on `state::class` (4b9d-ish prior fix);
apply the same pattern to the four screens that still flicker.
Inner content reads the outer `state` directly via `val s = state`
so the branch still has access to the typed value. Row-level diffs
are owned by LazyVerticalGrid / LazyColumn via item keys, so the
visual update is smooth and granular instead of a full fade.

Only Loading ↔ Success ↔ Error ↔ Empty transitions animate now —
the intended use of Crossfade. Same-kind state updates flow
through Compose's normal recomposition.

android/app/src/main/java/com/fabledsword/minstrel/library/ui/AlbumDetailScreen.kt

@@ -109,8 +109,11 @@ private fun AlbumDetailStateContent(
     playerViewModel: com.fabledsword.minstrel.player.ui.PlayerViewModel,
     navController: NavHostController,
 ) {
-    Crossfade(targetState = state, label = "album-detail") { s ->
-        when (s) {
+    // Crossfade keyed on `state::class` so a Success → fresh Success
+    // refresh (same kind, new detail) doesn't re-fade the whole body;
+    // only Loading ↔ Success ↔ Error transitions animate.
+    Crossfade(targetState = state::class, label = "album-detail") { _ ->
+        when (val s = state) {
             is AlbumDetailUiState.Loading ->
                 if (s.seed != null) SeededAlbumLoading(s.seed) else SkeletonTrackList()
             is AlbumDetailUiState.Error -> EmptyState(

android/app/src/main/java/com/fabledsword/minstrel/library/ui/ArtistDetailScreen.kt

@@ -87,8 +87,11 @@ fun ArtistDetailScreen(
             onRefresh = { viewModel.refresh().join() },
             modifier = Modifier.fillMaxSize().padding(inner),
         ) {
-            Crossfade(targetState = state, label = "artist-detail") { s ->
-                when (s) {
+            // Crossfade keyed on `state::class` so a Success → fresh
+            // Success refresh (same kind, new detail) doesn't re-fade
+            // the body; only Loading ↔ Success ↔ Error animate.
+            Crossfade(targetState = state::class, label = "artist-detail") { _ ->
+                when (val s = state) {
                     is ArtistDetailUiState.Loading ->
                         if (s.seed != null) {
                             SeededArtistLoading(s.seed)

android/app/src/main/java/com/fabledsword/minstrel/library/ui/LibraryScreen.kt

@@ -142,8 +142,13 @@ private fun ArtistsTab(
 ) {
     val state by viewModel.uiState.collectAsStateWithLifecycle()
     PullToRefreshScaffold(onRefresh = { viewModel.refresh().join() }) {
-        Crossfade(targetState = state, label = "library-artists") { s ->
-            when (s) {
+        // Crossfade is keyed on `state::class` (not the whole state)
+        // so a refresh that emits a fresh UiState.Success — same kind,
+        // new data — doesn't re-fade the entire grid. Only Loading ↔
+        // Success ↔ Error ↔ Empty transitions animate; row-level diff
+        // is owned by LazyVerticalGrid via its item keys.
+        Crossfade(targetState = state::class, label = "library-artists") { _ ->
+            when (val s = state) {
                 UiState.Loading -> SkeletonArtistsGrid()
                 UiState.Empty -> EmptyState(
                     title = "No artists yet",
@@ -170,8 +175,8 @@ private fun AlbumsTab(
 ) {
     val state by viewModel.uiState.collectAsStateWithLifecycle()
     PullToRefreshScaffold(onRefresh = { viewModel.refresh().join() }) {
-        Crossfade(targetState = state, label = "library-albums") { s ->
-            when (s) {
+        Crossfade(targetState = state::class, label = "library-albums") { _ ->
+            when (val s = state) {
                 UiState.Loading -> SkeletonAlbumsGrid()
                 UiState.Empty -> EmptyState(
                     title = "No albums yet",

android/app/src/main/java/com/fabledsword/minstrel/playlists/ui/PlaylistDetailScreen.kt

@@ -288,7 +288,10 @@ private fun PlaylistDetailContent(
     playerViewModel: com.fabledsword.minstrel.player.ui.PlayerViewModel,
     navController: NavHostController,
 ) {
-    Crossfade(targetState = state, label = "playlist-detail") { s -> when (s) {
+    // Crossfade keyed on `state::class` so refreshes that emit a
+    // fresh Success (same kind, new detail) don't re-fade the body;
+    // only Loading ↔ Success ↔ Error transitions animate.
+    Crossfade(targetState = state::class, label = "playlist-detail") { _ -> when (val s = state) {
         is PlaylistDetailUiState.Loading ->
             s.seed?.let { SeededPlaylistLoading(it) } ?: SkeletonPlaylistTrackList()
         is PlaylistDetailUiState.Error -> ErrorBlock(s.message, viewModel::refresh)