feat(album): display disc groups from catalog metadata

lib/screens/album_screen.dart

@@ -36,6 +36,7 @@ import 'package:spotiflac_android/widgets/track_detail_actions.dart';
 import 'package:spotiflac_android/widgets/selection_action_button.dart';
 import 'package:spotiflac_android/widgets/selection_bottom_bar.dart';
 import 'package:spotiflac_android/widgets/downloadable_cover.dart';
+import 'package:spotiflac_android/widgets/disc_separator_chip.dart';
 import 'package:spotiflac_android/widgets/mornye_artist_header.dart';
 
 class _AlbumCache {
@@ -628,6 +629,14 @@ class _AlbumScreenState extends ConsumerState<AlbumScreen>
     final existingHistoryKeys = ref.watch(
       downloadHistoryVisibleBatchExistsProvider(_historySnapshot.request),
     );
+    int discNumber(Track track) {
+      final number = track.discNumber ?? 1;
+      return number > 0 ? number : 1;
+    }
+
+    final hasMultipleDiscs = tracks.any(
+      (track) => discNumber(track) > 1 || (track.totalDiscs ?? 1) > 1,
+    );
     return SliverPadding(
       padding: EdgeInsets.symmetric(horizontal: wideListInset(context)),
       sliver: SliverList(
@@ -637,7 +646,7 @@ class _AlbumScreenState extends ConsumerState<AlbumScreen>
           final isInHistory = existingHistoryKeys.contains(
             historyLookups[index].lookupKey,
           );
-          return KeyedSubtree(
+          final row = KeyedSubtree(
             key: ValueKey(selectionId),
             child: StaggeredListItem(
               index: index,
@@ -675,6 +684,18 @@ class _AlbumScreenState extends ConsumerState<AlbumScreen>
               ),
             ),
           );
+          final disc = discNumber(track);
+          if (hasMultipleDiscs &&
+              (index == 0 || discNumber(tracks[index - 1]) != disc)) {
+            return Column(
+              crossAxisAlignment: CrossAxisAlignment.stretch,
+              children: [
+                DiscSeparatorChip(discNumber: disc),
+                row,
+              ],
+            );
+          }
+          return row;
         }, childCount: tracks.length),
       ),
     );

lib/widgets/animation_utils.dart

@@ -490,10 +490,12 @@ class _CollectionHeaderSkeleton extends StatelessWidget {
             children: [
               const SkeletonBox(width: 48, height: 48, borderRadius: 24),
               const SizedBox(width: 16),
-              SkeletonBox(
-                width: screenWidth * 0.45,
-                height: 48,
-                borderRadius: 24,
+              Flexible(
+                child: SkeletonBox(
+                  width: screenWidth * 0.45,
+                  height: 48,
+                  borderRadius: 24,
+                ),
               ),
               const SizedBox(width: 16),
               const SkeletonBox(width: 48, height: 48, borderRadius: 24),

lib/widgets/disc_separator_chip.dart

@@ -1,5 +1,6 @@
 import 'package:flutter/material.dart';
 import 'package:spotiflac_android/l10n/l10n.dart';
+import 'package:spotiflac_android/theme/mornye_theme.dart';
 
 /// "Disc N" chip with a trailing hairline, shown between disc groups in
 /// album track lists.
@@ -11,6 +12,28 @@ class DiscSeparatorChip extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     final colorScheme = Theme.of(context).colorScheme;
+    if (context.isMornye) {
+      return Padding(
+        padding: const EdgeInsets.fromLTRB(20, 20, 20, 8),
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            Divider(
+              height: 1,
+              color: MornyeTheme.metadataDividerColor(context),
+            ),
+            const SizedBox(height: 12),
+            Text(
+              context.l10n.downloadedAlbumDiscHeader(discNumber),
+              style: Theme.of(context).textTheme.titleSmall?.copyWith(
+                color: colorScheme.onSurfaceVariant,
+                fontWeight: FontWeight.w600,
+              ),
+            ),
+          ],
+        ),
+      );
+    }
 
     return Padding(
       padding: const EdgeInsets.fromLTRB(20, 16, 20, 8),