feat(CallFeature): implement call functionality and integrate WebSocket signaling

- Updated app.json to include microphone permissions and background audio support.
- Added call-related dependencies in package.json and package-lock.json.
- Enhanced ChatScreen to initiate calls and handle call actions.
- Introduced call components in the layout for incoming call handling.
- Expanded WebSocket service to manage call signaling messages and events.
- Refactored authStore to initialize call state on user authentication.

app/_layout.tsx

@@ -22,6 +22,7 @@ import AppDialogHost from '../src/components/common/AppDialogHost';
 import { installAlertOverride } from '../src/services/alertOverride';
 import { useAuthStore } from '../src/stores';
 import { checkForAPKUpdate } from '../src/services/apkUpdateService';
+import { CallScreen, IncomingCallModal, FloatingCallWindow } from '../src/components/call';
 
 registerNotificationPresentationHandler();
 
@@ -219,6 +220,9 @@ export default function RootLayout() {
             <ThemedStack />
             <AppPromptBar />
             <AppDialogHost />
+            <IncomingCallModal />
+            <CallScreen />
+            <FloatingCallWindow />
           </QueryClientProvider>
         </ThemedProviders>
       </SafeAreaProvider>