fix(android): UPnP select - loud logs on every code path

Two silent early returns in selectUpnp were swallowing the most
likely failure modes:
  - currentTrack null (nothing playing locally → can't cast a track)
  - transportFor() returns null (route disappeared or id mismatch)

On-device verification reported 'tap collapses the sheet but no
audio routes', with logcat empty - one of these was firing without
any signal.

Each early-return now Timber.w's why; the runCatching block adds
Timber.i breadcrumbs at every step (mint token, SetAVTransportURI,
Play, done) so the next failure shows exactly how far we got.

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

@@ -178,13 +178,28 @@ class OutputPickerController @Inject constructor(
      * deserialize / SOAP-parse code paths).
      */
     private suspend fun selectUpnp(route: OutputRoute) {
-        val trackId = playerController.uiState.value.currentTrack?.id ?: return
-        val transport = upnpDiscovery.transportFor(route.id) ?: return
+        val trackId = playerController.uiState.value.currentTrack?.id
+        if (trackId == null) {
+            Timber.w("UPnP select skipped: no currentTrack (start playback first)")
+            return
+        }
+        val transport = upnpDiscovery.transportFor(route.id)
+        if (transport == null) {
+            Timber.w(
+                "UPnP select skipped: no transport for route id=${route.id} " +
+                    "(route disappeared or id mismatch with discovery list)",
+            )
+            return
+        }
         runCatching {
+            Timber.i("UPnP select: mint token for track=$trackId, route=${route.name}")
             val token = castApi.streamToken(StreamTokenRequest(trackId = trackId))
+            Timber.i("UPnP select: SetAVTransportURI to ${token.url}")
             transport.setAVTransportURI(token.url)
+            Timber.i("UPnP select: Play")
             transport.play()
             playerController.pause()
+            Timber.i("UPnP select: done")
         }.onFailure { e ->
             Timber.w(e, "UPnP select failed for route ${route.id}")
         }