Keep the Android connection alive in the background

The session moves from the connection screen's ViewModel into an
app-wide SessionController, and a foreground service keeps the process
running while connected:

- Its notification shows the server and status and offers Mute, Deafen
  and Disconnect.
- It declares microphone use only once the microphone is handed to the
  connection, as Android requires that permission to be granted then.
- It holds a low-latency Wi-Fi lock and a CPU wake lock, since voice
  goes out every 20 ms.
- When the system moves to another network, the session reconnects to
  where it was, as its socket stays bound to the old one.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

android/gradle/libs.versions.toml

@@ -14,7 +14,7 @@ androidx-compose-bom = { module = "androidx.compose:compose-bom", version.ref =
 androidx-compose-material3 = { module = "androidx.compose.material3:material3" }
 androidx-compose-ui = { module = "androidx.compose.ui:ui" }
 androidx-lifecycle-runtime-compose = { module = "androidx.lifecycle:lifecycle-runtime-compose", version.ref = "lifecycle" }
-androidx-lifecycle-viewmodel-compose = { module = "androidx.lifecycle:lifecycle-viewmodel-compose", version.ref = "lifecycle" }
+androidx-lifecycle-service = { module = "androidx.lifecycle:lifecycle-service", version.ref = "lifecycle" }
 bouncycastle = { module = "org.bouncycastle:bcprov-jdk18on", version.ref = "bouncycastle" }
 ini4j = { module = "org.ini4j:ini4j", version.ref = "ini4j" }
 oboe = { module = "com.google.oboe:oboe", version.ref = "oboe" }