perf: Mumu截图增强启用但未生效时禁止运行，直到关闭增强或配置有效

src/MaaWpfGui/Main/AsstProxy.cs

@@ -541,11 +541,12 @@ namespace MaaWpfGui.Main
                         Instances.TaskQueueViewModel.AddLog(fastestScreencapString, color);
                         Instances.CopilotViewModel.AddLog(fastestScreencapString, color, showTime: false);
 
-                        // 截图增强未生效自动停止一次，再开就不管了
+                        // 截图增强未生效禁止启动
                         if (needToStop)
                         {
                             Execute.OnUIThreadAsync(async () =>
                             {
+                                Connected = false;
                                 await Instances.TaskQueueViewModel.Stop();
                                 Instances.TaskQueueViewModel.SetStopped();
                             });

src/MaaWpfGui/ViewModels/UI/SettingsViewModel.cs

@@ -3863,7 +3863,7 @@ namespace MaaWpfGui.ViewModels.UI
                 get => _enable;
                 set
                 {
-                    if (_enable == value)
+                    if (!SetAndNotify(ref _enable, value))
                     {
                         return;
                     }
@@ -3911,7 +3911,6 @@ namespace MaaWpfGui.ViewModels.UI
                     }
 
                     Instances.AsstProxy.Connected = false;
-                    SetAndNotify(ref _enable, value);
                     ConfigurationHelper.SetValue(ConfigurationKeys.MuMu12ExtrasEnabled, value.ToString());
                 }
             }