fix(mining-app): 移除遗留的 kDebugMode 调试代码

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/mining-app/lib/presentation/pages/contribution/contribution_records_page.dart

@@ -114,9 +114,6 @@ class _ContributionRecordsListPageState extends ConsumerState<ContributionRecord
     final isSelected = _selectedSourceType == type;
     return GestureDetector(
       onTap: () {
-        if (kDebugMode) {
-          print('[ContributionRecords] Filter tapped: $label (type: $type)');
-        }
         setState(() {
           _selectedSourceType = type;
           _currentPage = 1;