guard artist art resolution and tidy the preload

app/src/main/kotlin/com/subtracks/ui/components/HeroDetailScaffold.kt

@@ -73,6 +73,13 @@ import com.subtracks.ui.theme.heroDarkenAt
 private const val GRADIENT_SCREENS = 2.0f
 private const val FADE_DISTANCE_DP = 64
 
+/**
+ * A themed detail screen: endless artwork gradient, a fading top bar, and a lazy list whose first
+ * item is [header]. The header and its controls are measured so the bar fades in as they scroll off.
+ *
+ * [content] emits the rows after the header and assumes they share a uniform height, which is used
+ * to estimate the scroll offset for the bar.
+ */
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
 fun HeroDetailScaffold(

app/src/main/kotlin/com/subtracks/ui/library/ArtistDetailViewModel.kt

@@ -8,6 +8,7 @@ import com.subtracks.data.model.CoverArtRef
 import com.subtracks.data.repo.LibraryRepository
 import com.subtracks.data.repo.SourceRepository
 import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
@@ -39,12 +40,24 @@ class ArtistDetailViewModel(
             artist
                 .filterNotNull()
                 .collectLatest { loaded ->
-                    _art.value = sourceRepository.coverArt(loaded.coverArt)
-                    _artThumbnail.value = sourceRepository.coverArt(loaded.coverArt, thumbnail = true)
+                    val (full, thumbnail) = resolveArt(loaded)
+                    _art.value = full
+                    _artThumbnail.value = thumbnail
                 }
         }
     }
 
+    private suspend fun resolveArt(artist: Artist): Pair<CoverArtRef?, CoverArtRef?> {
+        repeat(3) { attempt ->
+            val full = sourceRepository.coverArt(artist.coverArt)
+            if (full != null) {
+                return full to sourceRepository.coverArt(artist.coverArt, thumbnail = true)
+            }
+            if (attempt < 2) delay(300)
+        }
+        return null to null
+    }
+
     fun coverArt(
         coverArt: String?,
         thumbnail: Boolean,

app/src/main/kotlin/com/subtracks/ui/library/PlaylistDetailScreen.kt

@@ -103,9 +103,13 @@ private fun playlistSummary(playlist: Playlist?): String {
 }
 
 private fun formatDuration(seconds: Long): String? {
-    if (seconds <= 0) return null
+    if (seconds < 60) return null
     val totalMinutes = seconds / 60
     val hours = totalMinutes / 60
     val minutes = totalMinutes % 60
-    return if (hours > 0) "$hours hr $minutes min" else "$totalMinutes min"
+    return when {
+        hours == 0L -> "$totalMinutes min"
+        minutes == 0L -> "$hours hr"
+        else -> "$hours hr $minutes min"
+    }
 }

app/src/main/kotlin/com/subtracks/ui/playback/NowPlayingScreen.kt

@@ -75,10 +75,7 @@ fun NowPlayingRoute(
     val thumbnail = controller.coverArt(state.item, thumbnail = true)
     LaunchedEffect(state.item?.id, state.hasNext) {
         if (!state.hasNext) return@LaunchedEffect
-        controller.upcomingCoverArt(thumbnail = true)?.let {
-            ArtworkSeedCache.prefetch(context, it)
-            prefetchImage(context, it)
-        }
+        controller.upcomingCoverArt(thumbnail = true)?.let { ArtworkSeedCache.prefetch(context, it) }
         controller.upcomingCoverArt()?.let { prefetchImage(context, it) }
     }
     NowPlayingScreen(