fixing a ton of sloppy mess...

walkguide-mobile/walkguide_app/lib/features/call/call_screen.dart

@@ -1,4 +1,4 @@
-// ignore_for_file: use_build_context_synchronously
+// ignore_for_file: use_build_context_synchronously, prefer_const_constructors
 // lib/features/call/call_screen.dart
 //
 // CallScreen        — user memanggil Guardian via Agora
@@ -34,8 +34,6 @@ class CallScreen extends StatefulWidget {
 
 class _CallScreenState extends State<CallScreen>
     with SingleTickerProviderStateMixin {
-  static const _channelName = 'walkguide-call';
-
   _CallPhase _phase = _CallPhase.calling;
   bool _muted = false;
   bool _speakerOn = true;
@@ -61,8 +59,7 @@ class _CallScreenState extends State<CallScreen>
   }
 
   Future<void> _startCall() async {
-    final joined =
-        await sl<CallService>().joinChannel(channelName: _channelName);
+    final joined = await sl<CallService>().callPairedUser();
 
     if (!mounted) return;