Add a new RoomThreadListScreen and hook it up to the RoomThreadListService

It will automatically paginate to fill the screen and update the list as updates come in.

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

@@ -179,6 +179,17 @@ struct RoomScreen: View {
                 }
             }
         }
+            if #available(iOS 26, *) {
+                ToolbarSpacer(.fixed, placement: .primaryAction)
+            }
+            
+            ToolbarItem(placement: .primaryAction) {
+                Button {
+                    context.send(viewAction: .displayThreadList)
+                } label: {
+                    CompoundIcon(\.threads)
+                }
+            }
     }
     
     @ViewBuilder