feat(android): NowPlaying output-picker integration

Bluetooth slice (5/5). Wires the OutputPickerViewModel + chip +
sheet into NowPlayingScreen.

- Chip renders between BottomActionsRow and ScrubberRow, hidden
  via shouldShowChip() when the only route is the built-in speaker
  (no useful picker with one option).
- Sheet appears on chip tap; selecting a route or dismissing flips
  the ViewModel state and downgrades MediaRouter discovery.
- BLUETOOTH_CONNECT permission requested via the modern
  ActivityResultContracts.RequestPermission() pattern on first
  sheet open. permissionDenied flag passed through to the sheet so
  the 'pair in Settings' hint renders when refused.

Closes the Bluetooth slice spec'd in
docs/superpowers/specs/2026-06-03-android-output-picker-bluetooth-design.md.
On-device verification still pending: pair a Bluetooth speaker,
confirm chip + sheet + select + audio routes; verify wired plug
auto-update + permission-denial hint + long-name truncation.

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

@@ -2,6 +2,10 @@
 
 package com.fabledsword.minstrel.player.ui
 
+import android.Manifest
+import android.content.pm.PackageManager
+import androidx.activity.compose.rememberLauncherForActivityResult
+import androidx.activity.result.contract.ActivityResultContracts
 import androidx.compose.animation.ExperimentalSharedTransitionApi
 import androidx.compose.foundation.background
 import androidx.compose.foundation.rememberScrollState
@@ -44,13 +48,17 @@ import androidx.compose.material3.Text
 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.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
+import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.unit.dp
+import androidx.core.content.ContextCompat
 import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.navigation.NavHostController
@@ -66,6 +74,11 @@ import com.composables.icons.lucide.Shuffle
 import com.composables.icons.lucide.SkipBack
 import com.composables.icons.lucide.SkipForward
 import com.fabledsword.minstrel.player.RepeatMode
+import com.fabledsword.minstrel.player.output.DeviceChip
+import com.fabledsword.minstrel.player.output.OutputPickerSheet
+import com.fabledsword.minstrel.player.output.OutputPickerViewModel
+import com.fabledsword.minstrel.player.output.OutputRoute
+import com.fabledsword.minstrel.player.output.RouteSnapshot
 import com.fabledsword.minstrel.nav.AlbumDetail
 import com.fabledsword.minstrel.nav.ArtistDetail
 import com.fabledsword.minstrel.nav.HERO_KEY_NOW_PLAYING_COVER
@@ -268,6 +281,32 @@ private fun NowPlayingBody(
 ) {
     val isLiked by trackActionsViewModel.isLikedFlow(track.id)
         .collectAsStateWithLifecycle(initialValue = false)
+    val outputViewModel: OutputPickerViewModel = hiltViewModel()
+    val routes by outputViewModel.routes.collectAsStateWithLifecycle()
+    val sheetVisible by outputViewModel.sheetVisible.collectAsStateWithLifecycle()
+
+    // One-shot BLUETOOTH_CONNECT permission flow. The launcher is
+    // remembered across recompositions; the LaunchedEffect fires
+    // exactly once when the sheet opens for the first time per
+    // composition. Subsequent opens are no-ops; the system remembers
+    // the user's choice.
+    val context = LocalContext.current
+    var permissionDenied by remember { mutableStateOf(false) }
+    val permissionLauncher = rememberLauncherForActivityResult(
+        contract = ActivityResultContracts.RequestPermission(),
+    ) { granted ->
+        permissionDenied = !granted
+    }
+    LaunchedEffect(sheetVisible) {
+        if (sheetVisible &&
+            ContextCompat.checkSelfPermission(
+                context,
+                Manifest.permission.BLUETOOTH_CONNECT,
+            ) != PackageManager.PERMISSION_GRANTED
+        ) {
+            permissionLauncher.launch(Manifest.permission.BLUETOOTH_CONNECT)
+        }
+    }
     Column(
         modifier = Modifier
             .fillMaxSize()
@@ -295,6 +334,17 @@ private fun NowPlayingBody(
             onToggleShuffle = viewModel::toggleShuffle,
             onCycleRepeat = viewModel::cycleRepeat,
         )
+        // Spec visibility rule: hide the chip when the only route is the
+        // built-in speaker — no picker is useful with one option. Chip
+        // reappears the moment a Bluetooth pair or wired plug arrives.
+        if (shouldShowChip(routes)) {
+            Spacer(Modifier.height(8.dp))
+            DeviceChip(
+                route = routes.current,
+                onClick = outputViewModel::onChipTapped,
+                modifier = Modifier.align(Alignment.CenterHorizontally),
+            )
+        }
         Spacer(Modifier.height(4.dp))
         val smoothPositionMs by rememberSmoothPositionMs(
             positionMs = state.positionMs,
@@ -314,6 +364,20 @@ private fun NowPlayingBody(
             onNext = viewModel::skipToNext,
         )
     }
+    if (sheetVisible) {
+        OutputPickerSheet(
+            snapshot = routes,
+            permissionDenied = permissionDenied,
+            onRouteSelected = outputViewModel::onRouteSelected,
+            onDismiss = outputViewModel::onSheetDismissed,
+        )
+    }
+}
+
+private fun shouldShowChip(snapshot: RouteSnapshot): Boolean {
+    val onlyBuiltIn = snapshot.available.size == 1 &&
+        snapshot.available.first().kind == OutputRoute.Kind.BuiltIn
+    return !onlyBuiltIn
 }
 
 @Composable