address the review: source title after a queue reorder, scrim timing, thumbnail painter

- derive the now playing fallback title from the current item for every kind except the songs list, so a track reordered into the album queue (now a Song entry) still shows its album
- reset the resolved title to the fallback when the queue context changes, so crossing albums does not briefly show the previous name
- start the now playing scrim fade later (0.85) so it darkens the sheet, not the library, while the sheet is still sliding up
- reuse the thumbnail's onSuccess painter ratio instead of loading a second thumbnail painter for the aspect ratio
- drop the now-unneeded ExperimentalLayoutApi opt-in on AddSourceScreen (imePadding is stable)

app/src/main/kotlin/com/subtracks/ui/AppRoot.kt

@@ -94,7 +94,7 @@ private const val OVERLAY_DURATION_MS = 200
 private const val EXPAND_FADE = 0.1f
 private const val FLING_VELOCITY = 1000f
 private const val MINI_PLAYER_ANIM_MS = 200
-private const val SCRIM_FADE_START = 0.6f
+private const val SCRIM_FADE_START = 0.85f
 
 private object Routes {
     const val LIBRARY = "library"

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

@@ -49,6 +49,7 @@ fun CoverArt(
     val context = LocalPlatformContext.current
     var failed by remember(ref, thumbnailRef) { mutableStateOf(false) }
     var thumbnailLoaded by remember(ref, thumbnailRef) { mutableStateOf(false) }
+    var thumbnailRatio by remember(ref, thumbnailRef) { mutableStateOf<Float?>(null) }
     val model = remember(ref, thumbnailRef) { ref?.let { imageRequest(context, it, crossfade = thumbnailRef != null) } }
     val frameModifier =
         Modifier
@@ -65,6 +66,7 @@ fun CoverArt(
                 failed = failed,
                 thumbnailLoaded = thumbnailLoaded,
                 onThumbnailLoaded = { thumbnailLoaded = true },
+                onThumbnailRatio = { thumbnailRatio = it },
                 contentScale = ContentScale.Crop,
             ) {
                 if (ref != null) {
@@ -85,15 +87,10 @@ fun CoverArt(
                 onError = { failed = true },
                 contentScale = ContentScale.Fit,
             )
-        val thumbnailPainter =
-            rememberAsyncImagePainter(
-                model = remember(thumbnailRef) { thumbnailRef?.let { imageRequest(context, it, crossfade = false) } },
-                contentScale = ContentScale.Fit,
-            )
         BoxWithConstraints(modifier, contentAlignment = Alignment.Center) {
             val ratio =
                 painter.intrinsicSize.ratioOrNull()
-                    ?: thumbnailPainter.intrinsicSize.ratioOrNull()
+                    ?: thumbnailRatio
                     ?: 1f
             val width = if (ratio > maxWidth.value / maxHeight.value) maxWidth else maxHeight * ratio
             Box(Modifier.size(width, width / ratio).then(frameModifier)) {
@@ -105,6 +102,7 @@ fun CoverArt(
                     failed = failed,
                     thumbnailLoaded = thumbnailLoaded,
                     onThumbnailLoaded = { thumbnailLoaded = true },
+                    onThumbnailRatio = { thumbnailRatio = it },
                     contentScale = ContentScale.Fit,
                 ) {
                     if (ref != null) {
@@ -130,6 +128,7 @@ private fun BoxScope.CoverArtContent(
     failed: Boolean,
     thumbnailLoaded: Boolean,
     onThumbnailLoaded: () -> Unit,
+    onThumbnailRatio: (Float) -> Unit,
     contentScale: ContentScale,
     main: @Composable () -> Unit,
 ) {
@@ -147,7 +146,12 @@ private fun BoxScope.CoverArtContent(
             model = remember(thumbnailRef) { imageRequest(context, thumbnailRef, crossfade = false) },
             contentDescription = null,
             contentScale = contentScale,
-            onSuccess = { onThumbnailLoaded() },
+            onSuccess = { success ->
+                onThumbnailLoaded()
+                success.painter.intrinsicSize
+                    .ratioOrNull()
+                    ?.let(onThumbnailRatio)
+            },
             modifier = Modifier.fillMaxSize(),
         )
     }

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

@@ -83,8 +83,14 @@ fun NowPlayingRoute(
     val art = controller.coverArt(state.item)
     val thumbnail = controller.coverArt(state.item, thumbnail = true)
     val queueContext = state.context
-    val fallbackTitle = if (queueContext?.kind == QueueKind.Album) state.item?.album.orEmpty() else "Library"
+    val fallbackTitle =
+        if (queueContext?.kind == QueueKind.Songs) {
+            "Library"
+        } else {
+            state.item?.album?.takeIf { it.isNotBlank() } ?: "Library"
+        }
     val sourceTitle by produceState<String>(initialValue = fallbackTitle, queueContext) {
+        value = fallbackTitle
         value = controller.sourceTitle(queueContext) ?: fallbackTitle
     }
     LaunchedEffect(state.item?.id, state.hasNext) {

app/src/main/kotlin/com/subtracks/ui/settings/AddSourceScreen.kt

@@ -2,7 +2,6 @@ package com.subtracks.ui.settings
 
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Column
-import androidx.compose.foundation.layout.ExperimentalLayoutApi
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
@@ -58,7 +57,7 @@ fun AddSourceRoute(
     )
 }
 
-@OptIn(ExperimentalMaterial3Api::class, ExperimentalLayoutApi::class)
+@OptIn(ExperimentalMaterial3Api::class)
 @Composable
 fun AddSourceScreen(
     state: AddSourceState,