fix(android): NowPlaying go-to-album/artist navigates atomically (audit v3 Bug-5)

The kebab "Go to album/artist" did popBackStack() then navigate() —
two transactions, leaving a visible frame on whichever shell tab sat
under NowPlaying before the detail pushed. Replaced with a single
navigate(...) { popUpTo(NowPlaying) { inclusive = true } } so the
modal is removed and the detail pushed in one atomic transaction,
no intermediate frame.

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

android/app/src/main/java/com/fabledsword/minstrel/player/ui/NowPlayingScreen.kt

@@ -67,6 +67,7 @@ import com.fabledsword.minstrel.nav.ArtistDetail
 import com.fabledsword.minstrel.nav.HERO_KEY_NOW_PLAYING_COVER
 import com.fabledsword.minstrel.nav.LocalAnimatedContentScope
 import com.fabledsword.minstrel.nav.LocalSharedTransitionScope
+import com.fabledsword.minstrel.nav.NowPlaying
 import com.fabledsword.minstrel.nav.Queue
 import com.fabledsword.minstrel.shared.widgets.LikeButton
 import com.fabledsword.minstrel.shared.widgets.trackactions.TrackActionsButton
@@ -293,13 +294,18 @@ private fun BottomActionsRow(
         TrackActionsButton(
             track = track,
             hideQueueActions = true,
+            // Single atomic transaction — navigate to the detail while
+            // popping NowPlaying off the back stack, so there's no
+            // intermediate frame on the shell tab underneath (Bug-5).
             onNavigateToAlbum = { id ->
-                navController.popBackStack()
-                navController.navigate(AlbumDetail(id))
+                navController.navigate(AlbumDetail(id)) {
+                    popUpTo(NowPlaying) { inclusive = true }
+                }
             },
             onNavigateToArtist = { id ->
-                navController.popBackStack()
-                navController.navigate(ArtistDetail(id))
+                navController.navigate(ArtistDetail(id)) {
+                    popUpTo(NowPlaying) { inclusive = true }
+                }
             },
         )
     }