Add a feature flag for the new RoomThreadList screen.

ElementX/Sources/Screens/RoomScreen/RoomScreenModels.swift

@@ -62,6 +62,7 @@ struct RoomScreenViewState: BindableState {
         isCallingEnabled && !isParticipatingInOngoingCall // Hide the join call button when already in the call
     }
     
+    var roomThreadListEnabled = false
     var isKnockingEnabled = false
     var isKnockableRoom = false
     var canAcceptKnocks = false

ElementX/Sources/Screens/RoomScreen/RoomScreenViewModel.swift

@@ -164,6 +164,10 @@ class RoomScreenViewModel: RoomScreenViewModelType, RoomScreenViewModelProtocol
     // MARK: - Private
     
     private func setupSubscriptions(ongoingCallRoomIDPublisher: CurrentValuePublisher<String?, Never>) {
+        appSettings.$roomThreadListEnabled
+            .weakAssign(to: \.state.roomThreadListEnabled, on: self)
+            .store(in: &cancellables)
+        
         appSettings.$knockingEnabled
             .weakAssign(to: \.state.isKnockingEnabled, on: self)
             .store(in: &cancellables)

ElementX/Sources/Screens/RoomScreen/View/RoomScreen.swift

@@ -179,6 +179,8 @@ struct RoomScreen: View {
                 }
             }
         }
+        
+        if context.viewState.roomThreadListEnabled {
             if #available(iOS 26, *) {
                 ToolbarSpacer(.fixed, placement: .primaryAction)
             }
@@ -190,6 +192,7 @@ struct RoomScreen: View {
                     CompoundIcon(\.threads)
                 }
             }
+        }
     }
     
     @ViewBuilder