fix(android): extract PlaylistCardCover to clear detekt LongMethod

Adding the play-button overlay in the previous commit pushed
PlaylistCard from 49 to 62 lines, two over detekt's 60-line cap.
Splitting the cover stack into its own private composable
(PlaylistCardCover) brings the outer function back under the limit
while keeping the call site readable.

Behavior identical to f17610ec; pure refactor for lint compliance.

android/app/src/main/java/com/fabledsword/minstrel/playlists/widgets/PlaylistCard.kt

@@ -60,37 +60,10 @@ fun PlaylistCard(
         color = Color.Transparent,
     ) {
         Column(modifier = Modifier.padding(horizontal = 8.dp)) {
-            CoverTile(
+            PlaylistCardCover(
-                url = playlist.coverUrl,
+                playlist = playlist,
-                contentDescription = playlist.name,
+                onPlay = onPlay,
-                size = 144.dp,
+                playEnabled = playEnabled,
-                fallback = {
-                    Icon(
-                        imageVector = Lucide.ListMusic,
-                        contentDescription = null,
-                        tint = MaterialTheme.colorScheme.onSurfaceVariant,
-                        modifier = Modifier.size(56.dp),
-                    )
-                },
-                overlay = {
-                    if (playlist.isSystem) {
-                        VariantPill(
-                            label = systemLabelFor(playlist.systemVariant),
-                            modifier = Modifier
-                                .align(Alignment.TopStart)
-                                .padding(6.dp),
-                        )
-                    }
-                    if (onPlay != null) {
-                        PlayCircleButton(
-                            onPlay = onPlay,
-                            enabled = playEnabled,
-                            modifier = Modifier
-                                .align(Alignment.BottomEnd)
-                                .padding(6.dp),
-                        )
-                    }
-                },
             )
             Spacer(Modifier.height(8.dp))
             Text(
@@ -111,6 +84,51 @@ fun PlaylistCard(
     }
 }
 
+/**
+ * 144dp cover with the system-variant pill (top-start) and play
+ * overlay (bottom-end) stacked on top. Pulled out of [PlaylistCard]
+ * to keep that composable under detekt's 60-line LongMethod cap.
+ */
+@Composable
+private fun PlaylistCardCover(
+    playlist: PlaylistRef,
+    onPlay: (suspend () -> Unit)?,
+    playEnabled: Boolean,
+) {
+    CoverTile(
+        url = playlist.coverUrl,
+        contentDescription = playlist.name,
+        size = 144.dp,
+        fallback = {
+            Icon(
+                imageVector = Lucide.ListMusic,
+                contentDescription = null,
+                tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                modifier = Modifier.size(56.dp),
+            )
+        },
+        overlay = {
+            if (playlist.isSystem) {
+                VariantPill(
+                    label = systemLabelFor(playlist.systemVariant),
+                    modifier = Modifier
+                        .align(Alignment.TopStart)
+                        .padding(6.dp),
+                )
+            }
+            if (onPlay != null) {
+                PlayCircleButton(
+                    onPlay = onPlay,
+                    enabled = playEnabled,
+                    modifier = Modifier
+                        .align(Alignment.BottomEnd)
+                        .padding(6.dp),
+                )
+            }
+        },
+    )
+}
+
 /** Small label chip overlaid on a system playlist's cover. */
 @Composable
 private fun VariantPill(label: String, modifier: Modifier = Modifier) {