fix: 管理会话自动恢复与访问来源统计优化

- 新增 AdminSessionRecover：后台离线/后端重启时自动重试恢复会话，明确失效才回跳登录
- 认证 cookie 契约调整（SameSite=Lax 与刷新轮转适配），路由与守卫适配
- 访问来源统计查询优化与测试、管理端 analytics sources 页面适配
- 移动端布局修正：覆盖 body min-h-screen 避免内容区高度异常

frontend/app/admin/analytics/sources/page.tsx

@@ -3,7 +3,7 @@
 import { useEffect, useState } from "react";
 import { AdminChartCard, NamedBarChart, NamedPieChart } from "@/components/admin/charts";
 import { apiStatsSources, type VisitSources } from "@/lib/api";
-import { RangeSegmented, StatsState, TableEmpty, refKindLabel } from "../ui";
+import { RangeSegmented, StatsState, TableEmpty, formatInt, refKindLabel } from "../ui";
 
 /** 来源按日表：固定展示四类主要来源列 */
 const TREND_KINDS = ["direct", "search", "social", "external"] as const;
@@ -49,11 +49,25 @@ export default function SourcesPage() {
       </AdminChartCard>
 
       <div className="grid gap-4 lg:grid-cols-2">
-        <AdminChartCard title="搜索引擎明细" hint="来自搜索结果页的浏览 Top 10">
-          {data.search_hosts.length ? (
-            <NamedBarChart data={data.search_hosts.map((h) => ({ label: h.key, count: h.count }))} />
+        <AdminChartCard title="站内搜索词 Top 10" hint="搜索结果页（/?q=）浏览量 Top 10">
+          {data.search_terms.length ? (
+            <ul className="flex flex-col divide-y max-h-[360px] overflow-y-auto" style={{ borderColor: "var(--line)" }}>
+              {data.search_terms.map((t, i) => (
+                <li key={`${i}-${t.key}`} className="py-2 flex items-center gap-3 text-[13px]">
+                  <span className="w-5 text-right tabular-nums shrink-0" style={{ color: "var(--ink-3)" }}>
+                    {i + 1}
+                  </span>
+                  <span className="flex-1 min-w-0 truncate" style={{ color: "var(--ink)" }} title={t.key}>
+                    {t.key}
+                  </span>
+                  <span className="tabular-nums shrink-0" style={{ color: "var(--ink-2)" }}>
+                    {formatInt(t.count)}
+                  </span>
+                </li>
+              ))}
+            </ul>
           ) : (
-            <TableEmpty text="暂无搜索引擎来源" />
+            <TableEmpty text="暂无站内搜索" />
           )}
         </AdminChartCard>
         <AdminChartCard title="外部链接明细" hint="其他站点跳转来源 Top 10">