feat: Zabbix 数据源管理 — 完整 CRUD + 双 Tab 数据源页面

后端:
- models/zabbix_datasource.go: Zabbix 数据源 model (15字段, 参照 Grafana)
- handlers/zabbix_datasource.go: CRUD + 测试连接 (调用 Zabbix API Auth)
- routes.go: /zabbix-datasources 路由组
- database.go: AutoMigrate

前端:
- api.ts: zabbixDatasourceApi
- ZabbixDatasourceManager.tsx: 表单 (URL/用户名/密码/Trends设置/DB直连)
- DatasourcePage.tsx: Prometheus + Zabbix 双 Tab 包装
- App.tsx: /datasources 路由更新

frontend/src/components/monitor/datasource/DatasourcePage.tsx

@@ -0,0 +1,47 @@
+// 数据源管理页面 — Prometheus + Zabbix 双 Tab // Logan.Li
+import { useState } from 'react';
+import { Database } from 'lucide-react';
+import { Tabs, TabsContent, TabsList, TabsTrigger } from '@/components/ui/tabs';
+import PrometheusDatasourceManager from '@/components/monitor/datasource/PrometheusDatasourceManager';
+import ZabbixDatasourceManager from '@/components/monitor/datasource/ZabbixDatasourceManager';
+
+export default function DatasourcePage() {
+  const [activeTab, setActiveTab] = useState('prometheus');
+
+  return (
+    <div className="space-y-4">
+      <div className="flex items-center gap-2">
+        <Database className="h-5 w-5 text-blue-400" />
+        <h1 className="text-xl font-bold text-[var(--dg-text-primary)]">数据源管理</h1>
+      </div>
+
+      <Tabs value={activeTab} onValueChange={setActiveTab}>
+        <TabsList className="bg-[var(--dg-bg-secondary)] border-[var(--dg-border)]">
+          <TabsTrigger value="prometheus" className="data-[state=active]:bg-orange-500/10 data-[state=active]:text-orange-400">
+            <img
+              src="https://cdn.jsdelivr.net/gh/walkxcode/dashboard-icons@master/png/prometheus.png"
+              className="w-4 h-4 rounded mr-1.5"
+              onError={(e) => { (e.target as HTMLImageElement).style.display = 'none'; }}
+            />
+            Prometheus
+          </TabsTrigger>
+          <TabsTrigger value="zabbix" className="data-[state=active]:bg-orange-500/10 data-[state=active]:text-orange-400">
+            <img
+              src="https://cdn.jsdelivr.net/gh/walkxcode/dashboard-icons@master/png/zabbix.png"
+              className="w-4 h-4 rounded mr-1.5"
+              onError={(e) => { (e.target as HTMLImageElement).style.display = 'none'; }}
+            />
+            Zabbix
+          </TabsTrigger>
+        </TabsList>
+
+        <TabsContent value="prometheus" className="mt-4">
+          <PrometheusDatasourceManager />
+        </TabsContent>
+        <TabsContent value="zabbix" className="mt-4">
+          <ZabbixDatasourceManager />
+        </TabsContent>
+      </Tabs>
+    </div>
+  );
+}