1.广角/主摄切换按钮已上移：

2.新增 isSwitchingLens 状态、避免切换镜头    stop 按钮禁用，不会触发 stopRecording
倍距按钮禁用，避免连续切换
ViewModel 层也兜底：isSwitchingLens=true 时直接拒绝 stop
3.合并失败兜底提示

lib/features/recording/widgets/widget_recording_hud.dart

@@ -18,6 +18,7 @@ class RecordingHudWidget extends StatelessWidget {
     required this.notificationsGranted,
     required this.isRecording,
     required this.isStartingRecording,
+    required this.isSwitchingLens,
     required this.isTouchLocked,
     this.showClipboardHint = false,
     this.clipboardAddress = '',
@@ -39,6 +40,7 @@ class RecordingHudWidget extends StatelessWidget {
   final bool notificationsGranted;
   final bool isRecording;
   final bool isStartingRecording;
+  final bool isSwitchingLens;
   final bool isTouchLocked;
   final bool showClipboardHint;
   final String clipboardAddress;
@@ -143,8 +145,9 @@ class RecordingHudWidget extends StatelessWidget {
           ),
         Positioned(
           right: 16.r,
-          bottom: _recordButtonBottom + _recordButtonSize + 14.h,
+          bottom: 260.r,
           child: _ZoomPresetControl(
+            enabled: !isSwitchingLens,
             zoomRatio: zoomRatio,
             minZoomRatio: minZoomRatio,
             maxZoomRatio: maxZoomRatio,
@@ -160,7 +163,7 @@ class RecordingHudWidget extends StatelessWidget {
             child: RecordingControlButton(
               isRecording: isRecording,
               isStartingRecording: isStartingRecording,
-              enabled: !isStartingRecording,
+              enabled: !isStartingRecording && !isSwitchingLens,
               size: _recordButtonSize,
               onTap: () {
                 if (isRecording) {
@@ -197,6 +200,7 @@ class RecordingHudWidget extends StatelessWidget {
 
 class _ZoomPresetControl extends StatelessWidget {
   const _ZoomPresetControl({
+    required this.enabled,
     required this.zoomRatio,
     required this.minZoomRatio,
     required this.maxZoomRatio,
@@ -204,6 +208,7 @@ class _ZoomPresetControl extends StatelessWidget {
     required this.onSelected,
   });
 
+  final bool enabled;
   final double zoomRatio;
   final double minZoomRatio;
   final double maxZoomRatio;
@@ -235,7 +240,7 @@ class _ZoomPresetControl extends StatelessWidget {
                 displayRatio: preset,
                 requestRatio: preset,
                 selected: _isPresetSelected(preset),
-                enabled: true,
+                enabled: enabled,
                 onSelected: onSelected,
               ),
           ],