实现缩放功能：增加缩放功能检索和设置方法，更新UI以支持缩放调整，增强缩放比例的状态管理。

lib/features/recording/pages/page_record.dart

@@ -357,10 +357,7 @@ class _PreviewLoadingLayer extends ConsumerWidget {
 }
 
 class _RecordingHudLayer extends ConsumerWidget {
-  const _RecordingHudLayer({
-    required this.onStart,
-    required this.onStop,
-  });
+  const _RecordingHudLayer({required this.onStart, required this.onStop});
 
   final Future<void> Function() onStart;
   final Future<void> Function() onStop;
@@ -378,6 +375,9 @@ class _RecordingHudLayer extends ConsumerWidget {
           m.session.isRecording,
           m.session.isStartingRecording,
           m.session.isTouchLocked,
+          m.session.zoomRatio,
+          m.session.minZoomRatio,
+          m.session.maxZoomRatio,
           m.hasValidClipboardInfo,
           m.clipboardRecordingModel.address.trim(),
         ),
@@ -392,6 +392,9 @@ class _RecordingHudLayer extends ConsumerWidget {
       isRecording,
       isStartingRecording,
       isTouchLocked,
+      zoomRatio,
+      minZoomRatio,
+      maxZoomRatio,
       showClipboardHint,
       clipboardAddress,
     ) = hudState;
@@ -406,6 +409,9 @@ class _RecordingHudLayer extends ConsumerWidget {
       isRecording: isRecording,
       isStartingRecording: isStartingRecording,
       isTouchLocked: isTouchLocked,
+      zoomRatio: zoomRatio,
+      minZoomRatio: minZoomRatio,
+      maxZoomRatio: maxZoomRatio,
       showClipboardHint: showClipboardHint,
       clipboardAddress: clipboardAddress,
       onStart: onStart,
@@ -419,9 +425,15 @@ class _RecordingHudLayer extends ConsumerWidget {
         await viewModel.refreshBatteryOptimization();
       },
       onToggleTouchLock: () {
-        final locked = ref.read(recordingViewModelProvider).session.isTouchLocked;
+        final locked = ref
+            .read(recordingViewModelProvider)
+            .session
+            .isTouchLocked;
         viewModel.setTouchLocked(!locked);
       },
+      onZoomSelected: (ratio) async {
+        await viewModel.setZoomRatio(ratio);
+      },
     );
   }
 }