调整对话框背景图适应方式，简化赛事信息复制按钮标签

lib/features/dialog/dialog-record.dart

@@ -107,7 +107,7 @@ class RecordDialog extends StatelessWidget {
                   Assets.images.imageDialogBg.path,
                   width: double.maxFinite,
                   height: 155.h,
-                  fit: BoxFit.cover,
+                  fit: BoxFit.fitWidth,
                 ),
               ),
               Column(

lib/features/recording/widgets/widget_record_header.dart

@@ -133,7 +133,7 @@ class _HeaderPasteActions extends StatelessWidget {
     return Row(
       mainAxisAlignment: MainAxisAlignment.end,
       children: [
-        _HeaderActionButton(label: '模拟复制赛事信息', onPressed: onMockCopy),
+        _HeaderActionButton(label: 'mock', onPressed: onMockCopy),
         _HeaderActionButton(
           label: '粘贴选手信息',
           onPressed: () => onPasteEventInfo(),