Empty state for Recipient Adress Book

frontend/pweb/lib/pages/address_book/page/empty.dart

@@ -0,0 +1,37 @@
+
+import 'package:flutter/material.dart';
+
+
+class RecipientAddressBookEmptyState extends StatelessWidget {
+  final String message;
+  final String actionLabel;
+  final VoidCallback onAction;
+
+  const RecipientAddressBookEmptyState({
+    required this.message,
+    required this.actionLabel,
+    required this.onAction,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final textTheme = Theme.of(context).textTheme;
+
+    return Center(
+      child: Column(
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          const Icon(Icons.contact_mail_outlined, size: 42),
+          const SizedBox(height: 12),
+          Text(message, style: textTheme.titleMedium),
+          const SizedBox(height: 12),
+          OutlinedButton.icon(
+            onPressed: onAction,
+            icon: const Icon(Icons.add),
+            label: Text(actionLabel),
+          ),
+        ],
+      ),
+    );
+  }
+}