feat(android): variant pill + mini-cover crossfade + clipboard API (audit v3 §4.10/§4.16 tail)

§4.10/§4.18 — PlaylistCard now overlays a small primary-tinted pill
on system-playlist covers showing the variant ("For You" / "Discover"
/ "Today's mix" / …) instead of relying on the subtitle line. The
subtitle now prefers track count, so system tiles show variant pill
+ track count rather than just the label.

§4.16 — MiniPlayer cover wraps its content in a Crossfade keyed on
coverUrl so artwork dissolves into the next track instead of hard-
swapping. Pairs with the CoverPrefetcher cache-warming so the next
cover is usually ready to fade in.

Cleanup — migrated the AdminUsers invite Copy-token button off the
deprecated LocalClipboardManager.setText to LocalClipboard.setClipEntry
(suspend, via rememberCoroutineScope + ClipData/ClipEntry), clearing
the build warning.

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

android/app/src/main/java/com/fabledsword/minstrel/admin/ui/AdminUsersScreen.kt

@@ -31,14 +31,16 @@ import androidx.compose.material3.Switch
 import androidx.compose.material3.Text
 import androidx.compose.material3.TextButton
 import androidx.compose.material3.TopAppBar
-import androidx.compose.ui.platform.LocalClipboardManager
-import androidx.compose.ui.text.AnnotatedString
+import android.content.ClipData
+import androidx.compose.ui.platform.ClipEntry
+import androidx.compose.ui.platform.LocalClipboard
 import com.fabledsword.minstrel.models.Invite
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
@@ -52,6 +54,7 @@ import com.fabledsword.minstrel.models.AdminUserRef
 import com.fabledsword.minstrel.nav.AdminUsers
 import com.fabledsword.minstrel.shared.widgets.MainAppBarActions
 import com.fabledsword.minstrel.shared.widgets.PullToRefreshScaffold
+import kotlinx.coroutines.launch
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
@@ -328,7 +331,8 @@ private fun GenerateInviteDialog(onDismiss: () -> Unit, onConfirm: (String?) ->
 
 @Composable
 private fun GeneratedInviteDialog(invite: Invite, onDismiss: () -> Unit) {
-    val clipboard = LocalClipboardManager.current
+    val clipboard = LocalClipboard.current
+    val scope = rememberCoroutineScope()
     AlertDialog(
         onDismissRequest = onDismiss,
         title = { Text("Invite created") },
@@ -350,7 +354,8 @@ private fun GeneratedInviteDialog(invite: Invite, onDismiss: () -> Unit) {
         confirmButton = {
             Button(
                 onClick = {
-                    clipboard.setText(AnnotatedString(invite.token))
+                    val clip = ClipData.newPlainText("Minstrel invite", invite.token)
+                    scope.launch { clipboard.setClipEntry(ClipEntry(clip)) }
                     onDismiss()
                 },
             ) {

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

@@ -1,5 +1,6 @@
 package com.fabledsword.minstrel.player.ui
 
+import androidx.compose.animation.Crossfade
 import androidx.compose.animation.ExperimentalSharedTransitionApi
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
@@ -75,19 +76,23 @@ private fun MiniCover(coverUrl: String, contentDescription: String) {
             .background(MaterialTheme.colorScheme.surfaceVariant),
         contentAlignment = Alignment.Center,
     ) {
-        if (coverUrl.isEmpty()) {
-            Icon(
-                imageVector = Lucide.Music,
-                contentDescription = null,
-                tint = MaterialTheme.colorScheme.onSurfaceVariant,
-            )
-        } else {
-            AsyncImage(
-                model = coverUrl,
-                contentDescription = contentDescription,
-                modifier = Modifier.size(COVER_SIZE_DP.dp),
-                contentScale = ContentScale.Crop,
-            )
+        // Cross-fade the artwork when the track changes so the cover
+        // dissolves into the next instead of hard-swapping.
+        Crossfade(targetState = coverUrl, label = "mini-cover") { url ->
+            if (url.isEmpty()) {
+                Icon(
+                    imageVector = Lucide.Music,
+                    contentDescription = null,
+                    tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            } else {
+                AsyncImage(
+                    model = url,
+                    contentDescription = contentDescription,
+                    modifier = Modifier.size(COVER_SIZE_DP.dp),
+                    contentScale = ContentScale.Crop,
+                )
+            }
         }
     }
 }

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

@@ -76,6 +76,14 @@ fun PlaylistCard(
                         contentScale = ContentScale.Crop,
                     )
                 }
+                if (playlist.isSystem) {
+                    VariantPill(
+                        label = systemLabelFor(playlist.systemVariant),
+                        modifier = Modifier
+                            .align(Alignment.TopStart)
+                            .padding(6.dp),
+                    )
+                }
             }
             Spacer(Modifier.height(8.dp))
             Text(
@@ -96,9 +104,29 @@ fun PlaylistCard(
     }
 }
 
+/** Small label chip overlaid on a system playlist's cover. */
+@Composable
+private fun VariantPill(label: String, modifier: Modifier = Modifier) {
+    if (label.isEmpty()) return
+    Surface(
+        modifier = modifier,
+        shape = RoundedCornerShape(FabledSwordFlatTokens.radiusSm),
+        color = MaterialTheme.colorScheme.primary.copy(alpha = PILL_BG_ALPHA),
+    ) {
+        Text(
+            text = label,
+            modifier = Modifier.padding(horizontal = 8.dp, vertical = 2.dp),
+            style = MaterialTheme.typography.labelSmall,
+            color = MaterialTheme.colorScheme.onPrimary,
+        )
+    }
+}
+
+private const val PILL_BG_ALPHA = 0.85f
+
 private fun subtitleFor(playlist: PlaylistRef): String = when {
-    playlist.isSystem -> systemLabelFor(playlist.systemVariant)
     playlist.trackCount > 0 -> "${playlist.trackCount} tracks"
+    playlist.isSystem -> systemLabelFor(playlist.systemVariant)
     else -> " "
 }