chore: release client-v1.0.61

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

client/lib/providers/session_heartbeat.dart

@@ -3,6 +3,7 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import '../core/api/api_client.dart';
 import '../core/auth/auth_state.dart';
+import '../core/config/app_constants.dart';
 import 'license_provider.dart';
 
 /// 登录态心跳：已登录时每 30s 执行一次 **单个** POST /auth/ping：
@@ -27,7 +28,7 @@ class SessionHeartbeat {
 
   void start() {
     _timer?.cancel();
-    _timer = Timer.periodic(const Duration(seconds: 30), (_) => _ping());
+    _timer = Timer.periodic(AppConstants.heartbeatInterval, (_) => _ping());
   }
 
   Future<void> _ping() async {