fix(access-logs): 修复概览域名筛选参数 hosts[] 被 Gin 忽略

Axios 默认序列化为 hosts[]=，Gin QueryArray("hosts") 读不到导致筛选失效；
后端兼容 hosts/hosts[]，前端改为重复键序列化。

frontend/lib/services/core/api-client.ts

@@ -28,6 +28,10 @@ const apiClient = axios.create({
   withCredentials: apiConfig.withCredentials,
   // Fail fast on slash redirect loops between Next dev proxy and Gin legacy routes.
   maxRedirects: 5,
+  // Gin QueryArray("hosts") expects hosts=a&hosts=b, not hosts[]=a.
+  paramsSerializer: {
+    indexes: null,
+  },
   headers: {
     'Content-Type': 'application/json',
   },