feat(android): UPnP selection state, disconnect, BuiltIn-pinned alphabetical sort

OutputPickerController now owns selection state for the UPnP leg and
runs the disconnect flow when the user picks a system route while a
renderer is active.

- Inject OkHttpClient + RemotePlayerState so we can build a
  RenderingControlClient at selection time and capture the last-known
  remote position on disconnect.
- selectUpnp publishes ActiveUpnp(routeId, routeName, avTransport,
  rendering) to ActiveUpnpHolder, marks the route id in
  selectedUpnpRouteIdInternal, and honors Sonos topology by routing
  through coordinatorRouteFor before SOAP.
- selectSystem now does the disconnect: AVTransport.Stop -> clear the
  holder -> seek local ExoPlayer to the remembered position -> resume
  if the remote was playing.
- routesState combines 4 sources (system, UPnP, Sonos topology,
  upnp-selected id). Non-coordinator Sonos members are filtered out
  of the visible list. current resolves from the merged list when a
  UPnP route is selected; otherwise from the system snapshot.
- sortRoutes drops the current-first rule -- BuiltIn "Phone speaker"
  pins to the top, everything else lowercase-alphabetical. Selection
  state moves to the radio-button indicator in the picker row.
- RemotePlayerState gets @Singleton + @Inject constructor() so Hilt
  can provide the shared instance to both the picker and the
  forthcoming MinstrelForwardingPlayer.

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

@@ -1,5 +1,8 @@
 package com.fabledsword.minstrel.player
 
+import javax.inject.Inject
+import javax.inject.Singleton
+
 /**
  * Synthesized state for the UPnP route -- what the ForwardingPlayer
  * exposes via Player.getCurrentPosition / isPlaying / etc. when the
@@ -14,7 +17,8 @@ package com.fabledsword.minstrel.player
  * consecutive poll failures = remote considered dropped (returns true
  * from recordPollFailure for the caller to surface). Success resets it.
  */
-class RemotePlayerState {
+@Singleton
+class RemotePlayerState @Inject constructor() {
 
     @Volatile var positionMs: Long = 0L; private set
     @Volatile var durationMs: Long = 0L; private set

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

@@ -6,8 +6,12 @@ import androidx.mediarouter.media.MediaRouteSelector
 import androidx.mediarouter.media.MediaRouter
 import com.fabledsword.minstrel.di.ApplicationScope
 import com.fabledsword.minstrel.player.PlayerController
+import com.fabledsword.minstrel.player.RemotePlayerState
 import com.fabledsword.minstrel.player.StreamTokenProvider
+import com.fabledsword.minstrel.player.output.upnp.RenderingControlClient
+import com.fabledsword.minstrel.player.output.upnp.SoapClient
 import com.fabledsword.minstrel.player.output.upnp.UpnpDiscoveryController
+import com.fabledsword.minstrel.player.output.upnp.sonos.SonosZoneGroup
 import dagger.hilt.android.qualifiers.ApplicationContext
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.flow.MutableStateFlow
@@ -16,6 +20,7 @@ import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.launch
+import okhttp3.OkHttpClient
 import timber.log.Timber
 import javax.inject.Inject
 import javax.inject.Singleton
@@ -23,9 +28,9 @@ import javax.inject.Singleton
 /**
  * Snapshot of the audio output route state. [current] is the live
  * route audio is being delivered to. [available] is every route the
- * picker knows about — MediaRouter system routes merged with
- * UPnP/DLNA renderers discovered on the LAN — sorted current-first
- * then by [OutputRoute.Kind] (Bluetooth, Wired, BuiltIn, Other).
+ * picker knows about -- MediaRouter system routes merged with
+ * UPnP/DLNA renderers discovered on the LAN -- with the BuiltIn
+ * "Phone speaker" pinned first, everything else alphabetical.
  */
 data class RouteSnapshot(
     val current: OutputRoute,
@@ -64,6 +69,8 @@ class OutputPickerController @Inject constructor(
     private val playerController: PlayerController,
     private val streamTokens: StreamTokenProvider,
     private val activeUpnpHolder: ActiveUpnpHolder,
+    private val remoteState: RemotePlayerState,
+    private val okHttp: OkHttpClient,
 ) {
     private val mediaRouter = MediaRouter.getInstance(context)
 
@@ -78,14 +85,34 @@ class OutputPickerController @Inject constructor(
      */
     private val systemRoutesInternal = MutableStateFlow(snapshotFromRouter())
 
+    private val selectedUpnpRouteIdInternal = MutableStateFlow<String?>(null)
+    private var lastKnownRemotePositionMs: Long = 0L
+
     val routesState: StateFlow<RouteSnapshot> = combine(
         systemRoutesInternal,
         upnpDiscovery.routes,
-    ) { sys, upnp ->
-        val merged = sys.available + upnp.map { OutputRoute.fromUpnpRoute(it) }
-        RouteSnapshot(current = sys.current, available = sortRoutes(sys.current, merged))
+        upnpDiscovery.sonosTopology,
+        selectedUpnpRouteIdInternal,
+    ) { sys, upnp, topology, upnpSelected ->
+        val suppressed = nonCoordinatorMemberUdns(topology)
+        val visibleUpnp = upnp
+            .filter { it.id.removePrefix("uuid:") !in suppressed }
+            .map { OutputRoute.fromUpnpRoute(it) }
+        val merged = sys.available + visibleUpnp
+        val current = if (upnpSelected != null) {
+            merged.firstOrNull { it.id == upnpSelected } ?: sys.current
+        } else {
+            sys.current
+        }
+        RouteSnapshot(current = current, available = sortRoutes(merged))
     }.stateIn(scope, SharingStarted.Eagerly, systemRoutesInternal.value)
 
+    private fun nonCoordinatorMemberUdns(topology: List<SonosZoneGroup>): Set<String> =
+        topology.flatMap { g ->
+            g.members.map { it.udn.removePrefix("uuid:") }
+                .filter { it != g.coordinatorUdn.removePrefix("uuid:") }
+        }.toSet()
+
     private val callback = object : MediaRouter.Callback() {
         override fun onRouteAdded(router: MediaRouter, route: MediaRouter.RouteInfo) =
             refresh()
@@ -159,6 +186,20 @@ class OutputPickerController @Inject constructor(
     }
 
     private fun selectSystem(route: OutputRoute) {
+        val wasUpnp = selectedUpnpRouteIdInternal.value
+        if (wasUpnp != null) {
+            val active = activeUpnpHolder.active.value
+            lastKnownRemotePositionMs = remoteState.positionMs
+            val wasPlayingRemote = remoteState.isPlaying
+            scope.launch {
+                runCatching { active?.avTransport?.stop() }
+                    .onFailure { Timber.w(it, "UPnP Stop failed during disconnect") }
+                activeUpnpHolder.set(null)
+                selectedUpnpRouteIdInternal.value = null
+                playerController.seekTo(lastKnownRemotePositionMs)
+                if (wasPlayingRemote) playerController.play()
+            }
+        }
         val target = mediaRouter.routes.firstOrNull { it.id == route.id } ?: return
         mediaRouter.selectRoute(target)
     }
@@ -179,16 +220,32 @@ class OutputPickerController @Inject constructor(
             Timber.w("UPnP select skipped: no currentTrack (start playback first)")
             return
         }
-        val transport = upnpDiscovery.transportFor(route.id)
+        // Honor Sonos topology: pick the coordinator's route when the user
+        // tapped a group row. Suppression in routesState already keeps the
+        // visible row at the coordinator's id, so this is identity in the
+        // common case -- defensive for follow-up flows.
+        val effectiveRoute = upnpDiscovery.coordinatorRouteFor(route.id)
+            ?.let { OutputRoute.fromUpnpRoute(it) } ?: route
+        val transport = upnpDiscovery.transportFor(effectiveRoute.id)
         if (transport == null) {
             Timber.w(
-                "UPnP select skipped: no transport for route id=${route.id} " +
+                "UPnP select skipped: no transport for route id=${effectiveRoute.id} " +
                     "(route disappeared or id mismatch with discovery list)",
             )
             return
         }
+        val rendering = renderingClientFor(effectiveRoute.id)
+        selectedUpnpRouteIdInternal.value = effectiveRoute.id
+        activeUpnpHolder.set(
+            ActiveUpnp(
+                routeId = effectiveRoute.id,
+                routeName = effectiveRoute.name,
+                avTransport = transport,
+                rendering = rendering,
+            ),
+        )
         runCatching {
-            Timber.i("UPnP select: mint token for track=$trackId, route=${route.name}")
+            Timber.i("UPnP select: mint token for track=$trackId, route=${effectiveRoute.name}")
             val token = streamTokens.mint(trackId)
             Timber.i("UPnP select: SetAVTransportURI to ${token.url} mime=${token.mime}")
             transport.setAVTransportURIWithMetadata(
@@ -201,10 +258,19 @@ class OutputPickerController @Inject constructor(
             playerController.pause()
             Timber.i("UPnP select: done")
         }.onFailure { e ->
-            Timber.w(e, "UPnP select failed for route ${route.id}")
+            Timber.w(e, "UPnP select failed for route ${effectiveRoute.id}")
+            activeUpnpHolder.set(null)
+            selectedUpnpRouteIdInternal.value = null
         }
     }
 
+    private fun renderingClientFor(routeId: String): RenderingControlClient? {
+        val rcUrl = upnpDiscovery.routes.value
+            .firstOrNull { it.id == routeId }
+            ?.renderingControlUrl ?: return null
+        return RenderingControlClient(SoapClient(okHttp), rcUrl)
+    }
+
     private fun refresh() {
         systemRoutesInternal.value = snapshotFromRouter()
     }
@@ -214,24 +280,16 @@ class OutputPickerController @Inject constructor(
             .filter { it.matchesSelector(selector) }
             .map { OutputRoute.fromRouteInfo(it) }
         val current = OutputRoute.fromRouteInfo(mediaRouter.selectedRoute)
-        return RouteSnapshot(current = current, available = sortRoutes(current, all))
+        return RouteSnapshot(current = current, available = sortRoutes(all))
     }
 
     /**
-     * Selected first, then Bluetooth, then Wired, then BuiltIn, then
-     * Other (UPnP renderers fall in Other). Keeps the active output at
-     * the top + likely-wanted alternatives next + fallback last.
+     * BuiltIn "Phone speaker" pinned first; everything else
+     * alphabetical. Selection state is conveyed by the radio button
+     * indicator in the picker row, not by sort order.
      */
-    private fun sortRoutes(current: OutputRoute, all: List<OutputRoute>): List<OutputRoute> {
-        val rank: (OutputRoute) -> Int = { route ->
-            when {
-                route.id == current.id -> 0
-                route.kind == OutputRoute.Kind.Bluetooth -> 1
-                route.kind == OutputRoute.Kind.Wired -> 2
-                route.kind == OutputRoute.Kind.BuiltIn -> 3
-                else -> 4
-            }
-        }
-        return all.sortedBy(rank)
+    private fun sortRoutes(all: List<OutputRoute>): List<OutputRoute> {
+        val (builtIn, rest) = all.partition { it.kind == OutputRoute.Kind.BuiltIn }
+        return builtIn + rest.sortedBy { it.name.lowercase() }
     }
 }