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/package.json

@@ -0,0 +1,19 @@
+{
+  "name": "dibby-wemo-android",
+  "version": "2.0.0",
+  "description": "Dibby Wemo Manager – Android companion app",
+  "private": true,
+  "scripts": {
+    "sync": "cap sync",
+    "open": "cap open android",
+    "build:apk": "cap sync && cd android && ./gradlew assembleDebug",
+    "build:release": "cap sync && cd android && ./gradlew assembleRelease"
+  },
+  "dependencies": {
+    "@capacitor/android": "^6.0.0",
+    "@capacitor/core": "^6.0.0"
+  },
+  "devDependencies": {
+    "@capacitor/cli": "^6.0.0"
+  }
+}