docs(android): expand node README

apps/android/README.md

@@ -1,10 +1,51 @@
 ## Clawdis Node (Android) (internal)
 
-Prototype Android “node” app (Iris parity): connects to the Gateway-owned bridge (`_clawdis-bridge._tcp`) over TCP and exposes Canvas + Chat + Camera.
+Modern Android “node” app (Iris parity): connects to the **Gateway-owned bridge** (`_clawdis-bridge._tcp`) over TCP and exposes **Canvas + Chat + Camera**.
 
-### Open in Android Studio
+Notes:
+- The node keeps the connection alive via a **foreground service** (persistent notification with a Disconnect action).
+- Chat always uses the shared session key **`main`** (same session across iOS/macOS/WebChat/Android).
+- Supports modern Android only (`minSdk 31`, Kotlin + Jetpack Compose).
+
+## Open in Android Studio
 - Open the folder `apps/android`.
 
-### Run
+## Build / Run
-- `./gradlew :app:installDebug`
 
+```bash
+cd apps/android
+./gradlew :app:assembleDebug
+./gradlew :app:installDebug
+./gradlew :app:testDebugUnitTest
+```
+
+`gradlew` auto-detects the Android SDK at `~/Library/Android/sdk` (macOS default) if `ANDROID_SDK_ROOT` / `ANDROID_HOME` are unset.
+
+## Connect / Pair
+
+1) Start the gateway (on your “master” machine):
+```bash
+pnpm clawdis gateway --port 18789 --verbose
+```
+
+2) In the Android app:
+- Open **Settings**
+- Either select a discovered bridge under **Discovered Bridges**, or use **Advanced → Manual Bridge** (host + port).
+
+3) Approve pairing (on the gateway machine):
+```bash
+clawdis nodes pending
+clawdis nodes approve <requestId>
+```
+
+More details: `docs/android/connect.md`.
+
+## Permissions
+
+- Discovery:
+  - Android 13+ (`API 33+`): `NEARBY_WIFI_DEVICES`
+  - Android 12 and below: `ACCESS_FINE_LOCATION` (required for NSD scanning)
+- Foreground service notification (Android 13+): `POST_NOTIFICATIONS`
+- Camera:
+  - `CAMERA` for `camera.snap` and `camera.clip`
+  - `RECORD_AUDIO` for `camera.clip` when `includeAudio=true`