perf(WT-1083): use Set<String> for handshake line lookup in callsToTerminate

Reduces membership checks from O(n) to O(1) per active call.

Author: SERDUN

lib/features/call/bloc/call_bloc.dart

@@ -2577,7 +2577,7 @@ class CallBloc extends Bloc<CallEvent, CallState> with WidgetsBindingObserver im
     final activeLineCallIds = [
       ...stateHandshake.lines,
       stateHandshake.guestLine,
-    ].whereType<Line>().map((line) => line.callId).toList();
+    ].whereType<Line>().map((line) => line.callId).toSet();
 
     for (final callId in state.callsToTerminate(activeLineCallIds)) {
       final activeCall = state.retrieveActiveCall(callId);

lib/features/call/bloc/call_state.dart

@@ -99,7 +99,7 @@ class CallState with _$CallState {
 
   bool get shouldListenToProximity => isActive && isVoiceChat && minimized != true;
 
-  List<String> callsToTerminate(List<String> activeLineCallIds) {
+  List<String> callsToTerminate(Set<String> activeLineCallIds) {
     final result = <String>[];
     activeCallsLoop:
     for (final activeCall in activeCalls) {

test/features/call/bloc/call_state_test.dart

@@ -1270,13 +1270,13 @@ void main() {
     test('terminates call absent from handshake lines', () {
       final call = _makeCall(callId: 'c1', processingStatus: CallProcessingStatus.connected);
       final state = CallState(activeCalls: [call]);
-      expect(state.callsToTerminate([]), ['c1']);
+      expect(state.callsToTerminate({}), ['c1']);
     });
 
     test('keeps call that is present in handshake lines', () {
       final call = _makeCall(callId: 'c1', processingStatus: CallProcessingStatus.connected);
       final state = CallState(activeCalls: [call]);
-      expect(state.callsToTerminate(['c1']), isEmpty);
+      expect(state.callsToTerminate({'c1'}), isEmpty);
     });
 
     test('keeps outgoing call with isPreOfferSent status absent from handshake', () {
@@ -1289,7 +1289,7 @@ void main() {
       ]) {
         final call = _makeCall(callId: 'c1', direction: CallDirection.outgoing, processingStatus: status);
         final state = CallState(activeCalls: [call]);
-        expect(state.callsToTerminate([]), isEmpty, reason: 'should skip $status');
+        expect(state.callsToTerminate({}), isEmpty, reason: 'should skip $status');
       }
     });
 
@@ -1300,7 +1300,7 @@ void main() {
         processingStatus: CallProcessingStatus.outgoingOfferSent,
       );
       final state = CallState(activeCalls: [call]);
-      expect(state.callsToTerminate([]), ['c1']);
+      expect(state.callsToTerminate({}), ['c1']);
     });
 
     test('terminates outgoing call at outgoingRinging absent from handshake', () {
@@ -1310,7 +1310,7 @@ void main() {
         processingStatus: CallProcessingStatus.outgoingRinging,
       );
       final state = CallState(activeCalls: [call]);
-      expect(state.callsToTerminate([]), ['c1']);
+      expect(state.callsToTerminate({}), ['c1']);
     });
 
     test('keeps outgoing isPreOfferSent call even if other calls are terminated', () {
@@ -1321,13 +1321,13 @@ void main() {
       );
       final dead = _makeCall(callId: 'dead', processingStatus: CallProcessingStatus.connected);
       final state = CallState(activeCalls: [inFlight, dead]);
-      expect(state.callsToTerminate([]), ['dead']);
+      expect(state.callsToTerminate({}), ['dead']);
     });
 
     test('returns empty when all calls are in handshake lines', () {
       final calls = [_makeCall(callId: 'c1'), _makeCall(callId: 'c2')];
       final state = CallState(activeCalls: calls);
-      expect(state.callsToTerminate(['c1', 'c2']), isEmpty);
+      expect(state.callsToTerminate({'c1', 'c2'}), isEmpty);
     });
   });
 }