Replace native Twilio Voice SDK with WebView-based softphone

Rewrites the mobile app from a native Twilio Voice SDK integration
(Android Telecom/ConnectionService) to a thin WebView shell that loads
a standalone browser phone page from WordPress. This eliminates the
buggy Android phone account registration, fixes frequent logouts by
using 7-day WP session cookies instead of JWT tokens, and maintains
all existing call features (dialpad, queues, hold, transfer, requeue,
recording, caller ID, agent status).

Server-side:
- Add class-twp-mobile-phone-page.php: standalone /twp-phone/ endpoint
  with mobile-optimized UI, dark mode, tab navigation, and Flutter
  WebView JS bridge
- Extend auth cookie to 7 days for phone agents
- Add WP AJAX handler for FCM token registration (cookie auth)

Flutter app (v2.0.0):
- Replace 18 native files with 5-file WebView shell
- Login via wp-login.php in WebView (auto-detect redirect on success)
- Full-screen WebView with auto microphone grant for WebRTC
- FCM push notifications preserved for queue alerts
- Remove: twilio_voice, dio, provider, JWT auth, SSE, native call UI

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

mobile/android/app/proguard-rules.pro

@@ -7,3 +7,8 @@
 
 # Flutter
 -keep class io.flutter.** { *; }
+
+# Play Core (not used but referenced by Flutter engine)
+-dontwarn com.google.android.play.core.splitcompat.SplitCompatApplication
+-dontwarn com.google.android.play.core.splitinstall.**
+-dontwarn com.google.android.play.core.tasks.**

mobile/android/app/src/main/AndroidManifest.xml

@@ -1,19 +1,17 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android">
 
-    <!-- Audio/Phone permissions for VoIP -->
+    <!-- Audio permissions for WebRTC -->
     <uses-permission android:name="android.permission.RECORD_AUDIO"/>
     <uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS"/>
     <uses-permission android:name="android.permission.BLUETOOTH"/>
     <uses-permission android:name="android.permission.BLUETOOTH_CONNECT"/>
 
-    <!-- Foreground service for active calls -->
+    <!-- Foreground service -->
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE"/>
-    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_PHONE_CALL"/>
 
     <!-- Full screen intent for incoming calls on lock screen -->
     <uses-permission android:name="android.permission.USE_FULL_SCREEN_INTENT"/>
     <uses-permission android:name="android.permission.WAKE_LOCK"/>
-    <uses-permission android:name="android.permission.MANAGE_OWN_CALLS"/>
 
     <!-- Push notifications -->
     <uses-permission android:name="android.permission.POST_NOTIFICATIONS"/>
@@ -23,7 +21,7 @@
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
 
     <application
-        android:label="TWP Softphone"
+        android:label="Twilio-WP"
         android:name="${applicationName}"
         android:icon="@mipmap/ic_launcher">
         <activity
@@ -51,14 +49,6 @@
                 <category android:name="android.intent.category.DEFAULT"/>
             </intent-filter>
         </activity>
-        <!-- Twilio Voice FCM handler — must have higher priority than Flutter's default -->
-        <service
-            android:name="com.twilio.twilio_voice.fcm.VoiceFirebaseMessagingService"
-            android:exported="false">
-            <intent-filter android:priority="10">
-                <action android:name="com.google.firebase.MESSAGING_EVENT" />
-            </intent-filter>
-        </service>
 
         <meta-data
             android:name="flutterEmbedding"

mobile/android/app/src/main/java/io/flutter/plugins/GeneratedPluginRegistrant.java

@@ -41,9 +41,9 @@ public final class GeneratedPluginRegistrant {
       Log.e(TAG, "Error registering plugin path_provider_android, io.flutter.plugins.pathprovider.PathProviderPlugin", e);
     }
     try {
-      flutterEngine.getPlugins().add(new com.twilio.twilio_voice.TwilioVoicePlugin());
+      flutterEngine.getPlugins().add(new io.flutter.plugins.webviewflutter.WebViewFlutterPlugin());
     } catch (Exception e) {
-      Log.e(TAG, "Error registering plugin twilio_voice, com.twilio.twilio_voice.TwilioVoicePlugin", e);
+      Log.e(TAG, "Error registering plugin webview_flutter_android, io.flutter.plugins.webviewflutter.WebViewFlutterPlugin", e);
     }
   }
 }