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

@@ -1,3 +1,4 @@
+@file:Suppress("TooManyFunctions") // discovery + Sonos topology + transport-lookup density
 package com.fabledsword.minstrel.player.output.upnp
 
 import android.content.Context
@@ -15,6 +16,7 @@ import okhttp3.HttpUrl
 import okhttp3.HttpUrl.Companion.toHttpUrlOrNull
 import okhttp3.OkHttpClient
 import okhttp3.Request
+import timber.log.Timber
 import javax.inject.Inject
 import javax.inject.Singleton
 
@@ -113,7 +115,9 @@ class UpnpDiscoveryController @Inject constructor(
         val zgtUrl = anySonos.zoneGroupTopologyControlUrl ?: return
         val groups = runCatching {
             ZoneGroupTopologyClient(SoapClient(okHttp), zgtUrl).getZoneGroupState()
-        }.getOrNull() ?: return
+        }
+            .onFailure { Timber.w(it, "refreshSonosTopology failed for %s", anySonos.id) }
+            .getOrNull() ?: return
         sonosTopologyInternal.value = groups
     }
 
@@ -124,13 +128,11 @@ class UpnpDiscoveryController @Inject constructor(
      * <UDN> carries it but Sonos's ZoneGroupState Coordinator attr does not.
      */
     fun coordinatorRouteFor(udn: String): UpnpRoute? {
-        val bare = udn.removePrefix("uuid:")
+        val bare = udn.bareUdn()
         val coord = sonosTopologyInternal.value
-            .firstOrNull { g -> g.members.any { it.udn.removePrefix("uuid:") == bare } }
+            .firstOrNull { g -> g.members.any { it.udn.bareUdn() == bare } }
             ?.coordinatorUdn ?: return null
-        return routesInternal.value.firstOrNull {
+        return routesInternal.value.firstOrNull { it.id.bareUdn() == coord.bareUdn() }
-            it.id.removePrefix("uuid:") == coord.removePrefix("uuid:")
-        }
     }
 
     /**
@@ -139,8 +141,8 @@ class UpnpDiscoveryController @Inject constructor(
      */
     fun nonCoordinatorMemberUdns(): Set<String> {
         return sonosTopologyInternal.value.flatMap { g ->
-            g.members.map { it.udn.removePrefix("uuid:") }
+            g.members.map { it.udn.bareUdn() }
-                .filter { it != g.coordinatorUdn.removePrefix("uuid:") }
+                .filter { it != g.coordinatorUdn.bareUdn() }
         }.toSet()
     }
 
@@ -208,3 +210,8 @@ class UpnpDiscoveryController @Inject constructor(
         val IP_SUFFIX_REGEX = Regex("""\s*\(\d+\.\d+\.\d+\.\d+\)$""")
     }
 }
+
+// uuid: prefix normalization — DeviceDescription <UDN> carries it; Sonos
+// ZoneGroupState Coordinator/UUID attrs don't. Helper centralizes the strip
+// so a future change to the convention isn't a silent compare-always-false bug.
+private fun String.bareUdn(): String = removePrefix("uuid:")

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

@@ -7,10 +7,10 @@ import okhttp3.HttpUrl
  * Bose SoundTouch, generic DLNA renderers). Lifted out of the SOAP /
  * SSDP details so the picker UI consumes a narrow domain shape.
  *
- * Generic UPnP only for THIS slice — Sonos-specific grouping value-adds
+ * Sonos devices additionally populate [zoneGroupTopologyControlUrl] from the
- * (group join/leave, zone topology) live in a separate Sonos extension
+ * ZoneGroupTopology service in their device description; non-Sonos devices
- * scoped in
+ * leave it null. The discovery controller uses that URL to aggregate stereo
- * docs/superpowers/specs/2026-06-03-android-output-picker-upnp-scope.md.
+ * pairs and multi-speaker groups into single picker rows.
  *
  * [id] is the device UDN (e.g. `uuid:RINCON_ABC...`). [name] is the
  * raw `<friendlyName>` straight from the device description — callers

android/app/src/test/java/com/fabledsword/minstrel/player/output/upnp/DeviceDescriptionTest.kt

@@ -58,6 +58,7 @@ class DeviceDescriptionTest {
             "http://192.168.1.50:1400/MediaRenderer/RenderingControl/Control",
             desc.renderingControlUrl?.toString(),
         )
+        assertNull(desc.zoneGroupTopologyControlUrl)
     }
 
     @Test