feat(api): 新增节点月流量限额强制下线

新增节点级月流量限额配置、重置调度和运行状态持久化
下发 traffic_limit 给 mi-node，并在超额后停止内核、到期后恢复
管理端支持编辑限额参数并展示额度进度、状态和下次重置
手动与定时重置会同步清理限额状态并通知节点刷新配置

app/Services/ServerService.php

@@ -241,10 +241,15 @@ class ServerService
             'api' => $metrics['api'] ?? [],
             'ws' => $metrics['ws'] ?? [],
             'limits' => $metrics['limits'] ?? [],
+            'traffic_limit' => $metrics['traffic_limit'] ?? null,
             'updated_at' => now()->timestamp,
             'kernel_status' => (bool) ($metrics['kernel_status'] ?? false),
         ];
 
+        if (isset($metrics['traffic_limit']) && is_array($metrics['traffic_limit'])) {
+            app(ServerTrafficLimitService::class)->applyRuntimeMetrics($node, $metrics['traffic_limit']);
+        }
+
         Cache::put(
             CacheKey::get('SERVER_' . $nodeType . '_METRICS', $nodeId),
             $metricsData,
@@ -397,6 +402,8 @@ class ServerService
             }
         }
 
+        $response['traffic_limit'] = app(ServerTrafficLimitService::class)->buildNodeConfig($node);
+
         return $response;
     }