사용하지 않는 파일 정리 전 백업 (Phase 10 완료 후 상태)

lib/screens/common/widgets/standard_states.dart

@@ -7,9 +7,9 @@ class StandardLoadingState extends StatelessWidget {
   final String message;
   
   const StandardLoadingState({
-    Key? key,
+    super.key,
     this.message = '데이터를 불러오는 중...',
-  }) : super(key: key);
+  });
 
   @override
   Widget build(BuildContext context) {
@@ -40,12 +40,12 @@ class StandardErrorState extends StatelessWidget {
   final IconData icon;
   
   const StandardErrorState({
-    Key? key,
+    super.key,
     this.title = '오류가 발생했습니다',
     this.message,
     this.onRetry,
     this.icon = Icons.error_outline,
-  }) : super(key: key);
+  });
 
   @override
   Widget build(BuildContext context) {
@@ -99,12 +99,12 @@ class StandardEmptyState extends StatelessWidget {
   final IconData icon;
   
   const StandardEmptyState({
-    Key? key,
+    super.key,
     this.title = '데이터가 없습니다',
     this.message,
     this.action,
     this.icon = Icons.inbox_outlined,
-  }) : super(key: key);
+  });
 
   @override
   Widget build(BuildContext context) {
@@ -154,12 +154,12 @@ class StandardInfoMessage extends StatelessWidget {
   final VoidCallback? onClose;
   
   const StandardInfoMessage({
-    Key? key,
+    super.key,
     required this.message,
     this.icon = Icons.info_outline,
     this.color,
     this.onClose,
-  }) : super(key: key);
+  });
 
   @override
   Widget build(BuildContext context) {
@@ -220,13 +220,13 @@ class StandardStatCard extends StatelessWidget {
   final String? subtitle;
   
   const StandardStatCard({
-    Key? key,
+    super.key,
     required this.title,
     required this.value,
     required this.icon,
     required this.color,
     this.subtitle,
-  }) : super(key: key);
+  });
 
   @override
   Widget build(BuildContext context) {