feat: Enhance container management UI with new management components and improved QR code generation flow

em2rp/lib/views/widgets/management/management_empty_state.dart

@@ -0,0 +1,38 @@
+import 'package:flutter/material.dart';
+
+/// Widget réutilisable pour afficher un état vide dans les listes de gestion
+class ManagementEmptyState extends StatelessWidget {
+  final IconData icon;
+  final String message;
+
+  const ManagementEmptyState({
+    super.key,
+    required this.icon,
+    required this.message,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    return Center(
+      child: Column(
+        mainAxisAlignment: MainAxisAlignment.center,
+        children: [
+          Icon(
+            icon,
+            size: 80,
+            color: Colors.grey.shade400,
+          ),
+          const SizedBox(height: 16),
+          Text(
+            message,
+            style: TextStyle(
+              fontSize: 18,
+              color: Colors.grey.shade600,
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
+