Ajout des permissions

em2rp/lib/widgets/permission_gate.dart

@@ -0,0 +1,42 @@
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+import 'package:em2rp/models/role_model.dart';
+import 'package:em2rp/providers/local_user_provider.dart';
+
+class PermissionGate extends StatelessWidget {
+  final Widget child;
+  final List<Permission> requiredPermissions;
+  final bool requireAll;
+  final Widget? fallback;
+
+  const PermissionGate({
+    super.key,
+    required this.child,
+    required this.requiredPermissions,
+    this.requireAll = true,
+    this.fallback,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    return Consumer<LocalUserProvider>(
+      builder: (context, localUserProvider, _) {
+        final currentUser = localUserProvider.currentUser;
+        if (currentUser == null) {
+          return fallback ?? const SizedBox.shrink();
+        }
+
+        final userRole = Roles.fromString(currentUser.role);
+        final hasPermission = requireAll
+            ? userRole.hasAllPermissions(requiredPermissions)
+            : userRole.hasAnyPermission(requiredPermissions);
+
+        if (hasPermission) {
+          return child;
+        }
+
+        return fallback ?? const SizedBox.shrink();
+      },
+    );
+  }
+}