fix(android): satisfy detekt — ReturnCount + LongMethod refactors

Three rule trips from the playback-errors + scrubber commits:

PlayerController.startRadio (4 returns → 2): extract the mid-queue
append branch into appendRadioToQueue(). startRadio just does the
guard checks and dispatches; the helper handles the cursor trim +
addMediaItems. Behavior identical.

PlayerController.onPlaybackStateChanged (4 returns → 2): extract
the duration check + zero-duration error emission + skip logic
into handleZeroDurationIfNeeded(). The listener stays compact (one
return for non-READY, one for repeat-evaluation guard); the helper
owns the failure path.

NowPlayingScreen.ScrubberRow (63 lines → ~50): extract the custom
track Box block into a ScrubTrack(fraction, accent) composable.
The Slider's `track` lambda becomes a one-line call. Pixel output
is identical.

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

@@ -200,21 +200,29 @@ class PlayerController @Inject constructor(
         val tracks = radio.seed(trackId)
         if (tracks.isEmpty()) return
         val source = "radio:$trackId"
-
         if (controller.mediaItemCount == 0) {
             setQueue(tracks, initialIndex = 0, source = source)
-            return
+        } else {
+            appendRadioToQueue(controller, tracks, trackId, source)
         }
+    }
 
+    /**
+     * Mid-queue radio insert. The current track keeps playing; every
+     * upcoming item is removed; the radio results are appended after.
+     * Drops the seed from the appended list when it matches the
+     * currently-playing track so it doesn't immediately repeat.
+     */
+    private fun appendRadioToQueue(
+        controller: MediaController,
+        tracks: List<TrackRef>,
+        seedTrackId: String,
+        source: String,
+    ) {
         val currentIdx = controller.currentMediaItemIndex
         val currentTrack = queueRefs.getOrNull(currentIdx)
-        // Server returns seed at index 0. Drop the duplicate when the
-        // seed is the currently playing track — otherwise append the
-        // full list so the current track is followed by the seed +
-        // recommendations.
-        val toAppend = if (currentTrack?.id == trackId) tracks.drop(1) else tracks
+        val toAppend = if (currentTrack?.id == seedTrackId) tracks.drop(1) else tracks
         if (toAppend.isEmpty()) return
-
         val nextIdx = currentIdx + 1
         if (nextIdx < controller.mediaItemCount) {
             controller.removeMediaItems(nextIdx, controller.mediaItemCount)
@@ -223,6 +231,31 @@ class PlayerController @Inject constructor(
         controller.addMediaItems(toAppend.map { it.toMediaItem(source) })
     }
 
+    /**
+     * When a STATE_READY transition for a freshly-loaded item reports
+     * a zero / TIME_UNSET duration, fire a `zero_duration` error event
+     * and advance past the dead track. Otherwise no-op.
+     */
+    private fun handleZeroDurationIfNeeded(controller: MediaController, idx: Int) {
+        val current = queueRefs.getOrNull(idx) ?: return
+        val duration = controller.duration
+        val isZeroDuration = duration <= 0L || duration == androidx.media3.common.C.TIME_UNSET
+        if (!isZeroDuration) return
+        playbackErrorEventsChannel.trySend(
+            PlaybackErrorEvent(
+                trackId = current.id,
+                kind = "zero_duration",
+                title = current.title.ifEmpty { "Track" },
+                detail = "duration=$duration",
+            ),
+        )
+        if (controller.hasNextMediaItem()) {
+            controller.seekToNextMediaItem()
+        } else {
+            controller.stop()
+        }
+    }
+
     // ── Internal: async connect + Listener-driven UI state sync ──────────
 
     private suspend fun connectAndObserve() {
@@ -271,26 +304,7 @@ class PlayerController @Inject constructor(
                     val idx = controller.currentMediaItemIndex
                     if (idx == lastEvaluatedItemIndex) return
                     lastEvaluatedItemIndex = idx
-                    val current = queueRefs.getOrNull(idx) ?: return
-                    val duration = controller.duration
-                    if (duration > 0L && duration != androidx.media3.common.C.TIME_UNSET) return
-                    // Zero-duration / unset-duration track: file decoded
-                    // to nothing playable. Fail fast — fire an error
-                    // event for the reporter (snackbar + server log) and
-                    // advance so the user doesn't sit on the dead track.
-                    playbackErrorEventsChannel.trySend(
-                        PlaybackErrorEvent(
-                            trackId = current.id,
-                            kind = "zero_duration",
-                            title = current.title.ifEmpty { "Track" },
-                            detail = "duration=$duration",
-                        ),
-                    )
-                    if (controller.hasNextMediaItem()) {
-                        controller.seekToNextMediaItem()
-                    } else {
-                        controller.stop()
-                    }
+                    handleZeroDurationIfNeeded(controller, idx)
                 }
 
                 override fun onEvents(player: Player, events: Player.Events) {

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

@@ -491,29 +491,8 @@ private fun ScrubberRow(positionMs: Long, durationMs: Long, onSeek: (Long) -> Un
                     .background(accent),
             )
         },
-        // Custom 4dp rounded track. M3's default Track is 16dp tall
-        // and reads as a heavy pill rather than a measurement line;
-        // making the thumb visibly taller than the track (14dp thumb
-        // on a 4dp bar) restores the "handle on a string" cue your
-        // eye reads as "tool, draggable." Also drops M3's stop
-        // indicator dot, which the web scrubber doesn't have.
-        track = { _ ->
-            Box(modifier = Modifier.fillMaxWidth().height(SCRUB_TRACK_HEIGHT_DP)) {
-                Box(
-                    modifier = Modifier
-                        .matchParentSize()
-                        .clip(RoundedCornerShape(SCRUB_TRACK_CORNER_DP))
-                        .background(MaterialTheme.colorScheme.surfaceVariant),
-                )
-                Box(
-                    modifier = Modifier
-                        .fillMaxWidth(fraction)
-                        .fillMaxHeight()
-                        .clip(RoundedCornerShape(SCRUB_TRACK_CORNER_DP))
-                        .background(accent),
-                )
-            }
-        },
+        // Custom 4dp rounded track — see ScrubTrack for rationale.
+        track = { _ -> ScrubTrack(fraction = fraction, accent = accent) },
     )
     Row(
         modifier = Modifier.fillMaxWidth(),
@@ -532,6 +511,34 @@ private fun ScrubberRow(positionMs: Long, durationMs: Long, onSeek: (Long) -> Un
     }
 }
 
+/**
+ * Custom 4dp rounded scrubber track. M3's default Track is 16dp tall
+ * and reads as a heavy pill rather than a measurement line; making
+ * the thumb visibly taller than the track (14dp thumb on a 4dp bar)
+ * restores the "handle on a string" cue your eye reads as "tool,
+ * draggable." Also drops M3's stop indicator dot, which the web
+ * scrubber doesn't have. Extracted so [ScrubberRow] stays under
+ * detekt's LongMethod ceiling.
+ */
+@Composable
+private fun ScrubTrack(fraction: Float, accent: Color) {
+    Box(modifier = Modifier.fillMaxWidth().height(SCRUB_TRACK_HEIGHT_DP)) {
+        Box(
+            modifier = Modifier
+                .matchParentSize()
+                .clip(RoundedCornerShape(SCRUB_TRACK_CORNER_DP))
+                .background(MaterialTheme.colorScheme.surfaceVariant),
+        )
+        Box(
+            modifier = Modifier
+                .fillMaxWidth(fraction)
+                .fillMaxHeight()
+                .clip(RoundedCornerShape(SCRUB_TRACK_CORNER_DP))
+                .background(accent),
+        )
+    }
+}
+
 @Composable
 private fun TransportRow(
     isPlaying: Boolean,