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/tests/unit/access-log-overview-params.test.ts

@@ -0,0 +1,22 @@
+import { describe, expect, it } from 'vitest';
+
+import { serializeSearchParams } from '@/lib/services/core/search-params';
+
+describe('serializeSearchParams', () => {
+  it('serializes hosts arrays as repeated keys for Gin QueryArray', () => {
+    const query = serializeSearchParams({
+      hours: 168,
+      hosts: ['gist.arctel.de'],
+    });
+    expect(query).toBe('hours=168&hosts=gist.arctel.de');
+  });
+
+  it('serializes multiple hosts without bracket notation', () => {
+    const query = serializeSearchParams({
+      hosts: ['a.example', 'b.example'],
+    });
+    expect(query).toBe('hosts=a.example&hosts=b.example');
+    expect(query).not.toContain('hosts[]');
+    expect(query).not.toContain('hosts%5B%5D');
+  });
+});