Add Android Capacitor app and build workflow

- apps/android/: Capacitor project wrapping the mobile web UI
- www/index.html: full DWM remote UI with first-run server IP setup screen
- capacitor.config.json: app ID com.dibby.wemo, allowMixedContent enabled
- .github/workflows/build-android.yml: builds debug APK on Ubuntu via Gradle

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/android/capacitor.config.json

@@ -0,0 +1,22 @@
+{
+  "appId": "com.dibby.wemo",
+  "appName": "Dibby Wemo",
+  "webDir": "www",
+  "server": {
+    "androidScheme": "https"
+  },
+  "android": {
+    "allowMixedContent": true,
+    "captureInput": true,
+    "webContentsDebuggingEnabled": false
+  },
+  "plugins": {
+    "SplashScreen": {
+      "launchAutoHide": true,
+      "launchShowDuration": 1000,
+      "backgroundColor": "#0d1b27",
+      "androidSplashResourceName": "splash",
+      "showSpinner": false
+    }
+  }
+}