feat(android): MiniPlayer prev/next + inline scrubber + like button

Audit v2 priority #8 — daily-touch player polish. MiniPlayer was
just cover + title + play-pause + kebab; now matches Flutter:

* Slim 4dp Slider at the top of the bar (Material3 thumb + active
  primary, no labels — those live on NowPlaying).
* Row: cover | title/artist | LikeButton | Prev | Play/Pause | Next | kebab.
* The cover-and-title region is the only part that expands to
  NowPlaying on tap; each IconButton handles its own click so a
  prev/next tap doesn't accidentally open the full player.

Bar height bumped 64 → 80dp to fit the slider above the row.
LikeButton sources its state from the shell-level TrackActionsViewModel
already plumbed through ShellScaffold (same hiltViewModel() instance).

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

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

@@ -15,6 +15,8 @@ import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Slider
+import androidx.compose.material3.SliderDefaults
 import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
@@ -32,12 +34,18 @@ import com.composables.icons.lucide.Lucide
 import com.composables.icons.lucide.Music
 import com.composables.icons.lucide.Pause
 import com.composables.icons.lucide.Play
+import com.composables.icons.lucide.SkipBack
+import com.composables.icons.lucide.SkipForward
+import com.fabledsword.minstrel.models.TrackRef
+import com.fabledsword.minstrel.shared.widgets.LikeButton
 import com.fabledsword.minstrel.shared.widgets.trackactions.TrackActionsButton
+import com.fabledsword.minstrel.shared.widgets.trackactions.TrackActionsViewModel
 import com.fabledsword.minstrel.theme.FabledSwordFlatTokens
 
-private const val MINI_BAR_HEIGHT_DP = 64
+private const val MINI_BAR_HEIGHT_DP = 80
 private const val MINI_BAR_TONAL_ELEVATION_DP = 4
 private const val COVER_SIZE_DP = 48
+private const val SCRUBBER_ROW_HEIGHT_DP = 4
 
 @Composable
 private fun MiniCover(coverUrl: String, contentDescription: String) {
@@ -71,9 +79,14 @@ private fun MiniCover(coverUrl: String, contentDescription: String) {
  * fresh install. Tapping the body navigates to the full
  * NowPlayingScreen via [onExpandClick].
  *
- * Cover comes from TrackRef.coverUrl (derived from albumId via the
- * BaseUrlInterceptor placeholder); falls back to the Lucide.Music
- * icon when the album binding is missing.
+ * Layout (Column):
+ *   - Slim seek slider at the top (4dp track)
+ *   - Row: cover | title/artist column | like | prev | play/pause | next | kebab
+ *
+ * The slider participates in pointer-events so tap/scrub works
+ * without the surface's onClick eating the gesture; the row's
+ * surface-level clickable still expands to NowPlaying on tap of
+ * the cover/title area.
  */
 @Composable
 fun MiniPlayer(
@@ -82,20 +95,92 @@ fun MiniPlayer(
     onNavigateToArtist: (String) -> Unit,
     modifier: Modifier = Modifier,
     viewModel: PlayerViewModel = hiltViewModel(),
+    trackActionsViewModel: TrackActionsViewModel = hiltViewModel(),
 ) {
     val state by viewModel.uiState.collectAsStateWithLifecycle()
     val track = state.currentTrack ?: return
+    val isLiked by trackActionsViewModel.isLikedFlow(track.id)
+        .collectAsStateWithLifecycle(initialValue = false)
 
     Surface(
         modifier = modifier
             .fillMaxWidth()
-            .height(MINI_BAR_HEIGHT_DP.dp)
-            .clickable(onClick = onExpandClick),
+            .height(MINI_BAR_HEIGHT_DP.dp),
         color = MaterialTheme.colorScheme.surface,
         tonalElevation = MINI_BAR_TONAL_ELEVATION_DP.dp,
     ) {
+        Column {
+            MiniSeekBar(
+                positionMs = state.positionMs,
+                durationMs = state.durationMs,
+                onSeek = viewModel::seekTo,
+            )
+            MiniRow(
+                track = track,
+                isPlaying = state.isPlaying,
+                isLiked = isLiked,
+                onExpandClick = onExpandClick,
+                onPlayPause = { if (state.isPlaying) viewModel.pause() else viewModel.play() },
+                onPrev = viewModel::skipToPrevious,
+                onNext = viewModel::skipToNext,
+                onToggleLike = {
+                    trackActionsViewModel.toggleLike(track.id, isLiked)
+                },
+                onNavigateToAlbum = onNavigateToAlbum,
+                onNavigateToArtist = onNavigateToArtist,
+            )
+        }
+    }
+}
+
+@Composable
+private fun MiniSeekBar(positionMs: Long, durationMs: Long, onSeek: (Long) -> Unit) {
+    val fraction = if (durationMs > 0) {
+        (positionMs.toFloat() / durationMs.toFloat()).coerceIn(0f, 1f)
+    } else {
+        0f
+    }
+    Slider(
+        value = fraction,
+        onValueChange = { v -> if (durationMs > 0) onSeek((v * durationMs).toLong()) },
+        modifier = Modifier
+            .fillMaxWidth()
+            .height(SCRUBBER_ROW_HEIGHT_DP.dp),
+        colors = SliderDefaults.colors(
+            thumbColor = MaterialTheme.colorScheme.primary,
+            activeTrackColor = MaterialTheme.colorScheme.primary,
+        ),
+    )
+}
+
+@Composable
+@Suppress("LongParameterList")
+private fun MiniRow(
+    track: TrackRef,
+    isPlaying: Boolean,
+    isLiked: Boolean,
+    onExpandClick: () -> Unit,
+    onPlayPause: () -> Unit,
+    onPrev: () -> Unit,
+    onNext: () -> Unit,
+    onToggleLike: () -> Unit,
+    onNavigateToAlbum: (String) -> Unit,
+    onNavigateToArtist: (String) -> Unit,
+) {
+    Row(
+        modifier = Modifier
+            .fillMaxWidth()
+            .padding(horizontal = 12.dp),
+        verticalAlignment = Alignment.CenterVertically,
+    ) {
+        // Cover + title area expands to NowPlaying on tap, but the
+        // transport buttons + kebab don't (each IconButton handles
+        // its own clicks). Wrap only the cover-and-title region with
+        // the clickable modifier rather than the whole row.
         Row(
-            modifier = Modifier.padding(horizontal = 12.dp),
+            modifier = Modifier
+                .weight(1f)
+                .clickable(onClick = onExpandClick),
             verticalAlignment = Alignment.CenterVertically,
         ) {
             MiniCover(coverUrl = track.coverUrl, contentDescription = track.title)
@@ -116,23 +201,36 @@ fun MiniPlayer(
                     overflow = TextOverflow.Ellipsis,
                 )
             }
-            IconButton(
-                onClick = { if (state.isPlaying) viewModel.pause() else viewModel.play() },
-            ) {
-                Icon(
-                    imageVector = if (state.isPlaying) Lucide.Pause else Lucide.Play,
-                    contentDescription = if (state.isPlaying) "Pause" else "Play",
-                    tint = MaterialTheme.colorScheme.onSurface,
-                )
-            }
-            // hideQueueActions=true: the playing track is itself the
-            // queue entry, so Play next / Add to queue would be silly.
-            TrackActionsButton(
-                track = track,
-                hideQueueActions = true,
-                onNavigateToAlbum = onNavigateToAlbum,
-                onNavigateToArtist = onNavigateToArtist,
+        }
+        LikeButton(liked = isLiked, onToggle = onToggleLike)
+        IconButton(onClick = onPrev) {
+            Icon(
+                imageVector = Lucide.SkipBack,
+                contentDescription = "Previous",
+                tint = MaterialTheme.colorScheme.onSurface,
             )
         }
+        IconButton(onClick = onPlayPause) {
+            Icon(
+                imageVector = if (isPlaying) Lucide.Pause else Lucide.Play,
+                contentDescription = if (isPlaying) "Pause" else "Play",
+                tint = MaterialTheme.colorScheme.onSurface,
+            )
+        }
+        IconButton(onClick = onNext) {
+            Icon(
+                imageVector = Lucide.SkipForward,
+                contentDescription = "Next",
+                tint = MaterialTheme.colorScheme.onSurface,
+            )
+        }
+        // hideQueueActions=true: the playing track is itself the
+        // queue entry, so Play next / Add to queue would be silly.
+        TrackActionsButton(
+            track = track,
+            hideQueueActions = true,
+            onNavigateToAlbum = onNavigateToAlbum,
+            onNavigateToArtist = onNavigateToArtist,
+        )
     }
 }