feat(android): output picker foundation - mediarouter + OutputRoute

Bluetooth slice (1/5). Adds the androidx.mediarouter 1.7.0 dep,
declares BLUETOOTH_CONNECT (needed on Android 12+ to enumerate
paired BT devices by name), and lays down the OutputRoute domain
model.

OutputRoute decouples the picker UI from MediaRouter.RouteInfo
(framework class, can't be constructed in JVM tests - same
constraint we hit with LikeMediaCallback). The Protocol enum
includes UPNP/CAST/SONOS placeholders so the next slice slots in
without a data-model rename - see
docs/superpowers/specs/2026-06-03-android-output-picker-upnp-scope.md
for the deferred work.

Controller + ViewModel + Compose UI land in follow-up commits.

android/gradle/libs.versions.toml

@@ -22,6 +22,7 @@ kotlinx-coroutines = "1.9.0"
 kotlinx-datetime = "0.6.1"
 kotlinx-serialization-converter = "1.0.0"
 media3 = "1.10.1"
+mediarouter = "1.7.0"
 coil = "3.0.0-rc02"
 palette = "1.0.0"
 timber = "5.0.1"
@@ -71,6 +72,7 @@ media3-exoplayer = { module = "androidx.media3:media3-exoplayer", version.ref =
 media3-session = { module = "androidx.media3:media3-session", version.ref = "media3" }
 media3-datasource-okhttp = { module = "androidx.media3:media3-datasource-okhttp", version.ref = "media3" }
 media3-ui = { module = "androidx.media3:media3-ui", version.ref = "media3" }
+mediarouter = { module = "androidx.mediarouter:mediarouter", version.ref = "mediarouter" }
 coil-compose = { module = "io.coil-kt.coil3:coil-compose", version.ref = "coil" }
 coil-network-okhttp = { module = "io.coil-kt.coil3:coil-network-okhttp", version.ref = "coil" }
 androidx-palette = { module = "androidx.palette:palette-ktx", version.ref = "palette" }