feat: 用户端访问足迹统计（IP 去重 UV/PV）

- 后端 Visit 模型(date+ip 唯一索引)：POST /api/track 埋点(ClientIP upsert，pv+1)，GET /api/admin/visits 每日 UV/PV 统计
- web 每会话上报一次访问(sessionStorage 防重)，IP 由后端去重
- admin 访问统计页：侧边栏入口 + 今日/近N天 UV·PV 卡片 + 每日柱状趋势(自绘无依赖) + 7/30/90 天切换

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

admin/src/App.tsx

@@ -5,6 +5,7 @@ import LoginPage from '@/pages/login'
 import DashboardPage from '@/pages/dashboard'
 import PostsListPage from '@/pages/posts-list'
 import PostEditPage from '@/pages/post-edit'
+import VisitsPage from '@/pages/visits'
 
 function RequireAuth() {
   if (!getToken()) return <Navigate to="/login" replace />
@@ -21,6 +22,7 @@ export default function App() {
           <Route path="posts" element={<PostsListPage />} />
           <Route path="posts/new" element={<PostEditPage />} />
           <Route path="posts/:id" element={<PostEditPage />} />
+          <Route path="visits" element={<VisitsPage />} />
         </Route>
       </Route>
       <Route path="*" element={<Navigate to="/" replace />} />

admin/src/api/visits.ts

@@ -0,0 +1,20 @@
+import { request } from '@/api/client'
+
+export interface DailyVisit {
+  date: string
+  uv: number
+  pv: number
+}
+
+export interface VisitStats {
+  daily: DailyVisit[]
+  total_uv: number
+  total_pv: number
+  today_uv: number
+  today_pv: number
+  days: number
+}
+
+export function fetchVisits(days: number) {
+  return request<VisitStats>(`/api/admin/visits?days=${days}`)
+}

admin/src/components/admin-sidebar.tsx

@@ -1,5 +1,13 @@
 import { Link, NavLink, useNavigate } from 'react-router-dom'
-import { FileText, LayoutDashboard, LogOut, Moon, Sun, X } from 'lucide-react'
+import {
+  BarChart3,
+  FileText,
+  LayoutDashboard,
+  LogOut,
+  Moon,
+  Sun,
+  X,
+} from 'lucide-react'
 import { logout } from '@/api/auth'
 import { useTheme } from '@/components/theme-provider'
 import { LogoMark } from '@/components/logo'
@@ -8,6 +16,7 @@ import { cn } from '@/lib/utils'
 const NAV = [
   { to: '/', label: '仪表盘', icon: LayoutDashboard, end: true },
   { to: '/posts', label: '文章', icon: FileText, end: false },
+  { to: '/visits', label: '访问统计', icon: BarChart3, end: false },
 ]
 
 interface Props {

admin/src/pages/visits.tsx

@@ -0,0 +1,117 @@
+import { useEffect, useState } from 'react'
+import { Eye, Users } from 'lucide-react'
+import { fetchVisits, type VisitStats } from '@/api/visits'
+import { cn } from '@/lib/utils'
+
+const RANGES = [7, 30, 90]
+
+export default function VisitsPage() {
+  const [days, setDays] = useState(30)
+  const [data, setData] = useState<VisitStats | null>(null)
+  const [error, setError] = useState('')
+
+  useEffect(() => {
+    let cancelled = false
+    fetchVisits(days)
+      .then((d) => {
+        if (!cancelled) setData(d)
+      })
+      .catch((e: Error) => {
+        if (!cancelled) setError(e.message)
+      })
+    return () => {
+      cancelled = true
+    }
+  }, [days])
+
+  // 补全连续日期，缺失天补 0，趋势图才连贯
+  const map = new Map((data?.daily ?? []).map((r) => [r.date, r]))
+  const series = Array.from({ length: days }, (_, i) => {
+    const d = new Date()
+    d.setDate(d.getDate() - (days - 1 - i))
+    const date = d.toISOString().slice(0, 10)
+    return map.get(date) ?? { date, uv: 0, pv: 0 }
+  })
+  const maxUv = Math.max(1, ...series.map((s) => s.uv))
+
+  const cards = [
+    { label: '今日访客 UV', value: data?.today_uv, icon: Users },
+    { label: '今日访问 PV', value: data?.today_pv, icon: Eye },
+    { label: `近 ${days} 天访客`, value: data?.total_uv, icon: Users },
+    { label: `近 ${days} 天访问`, value: data?.total_pv, icon: Eye },
+  ]
+
+  return (
+    <div>
+      <div className="mb-6 flex flex-wrap items-center justify-between gap-3">
+        <div>
+          <h1 className="text-[22px] font-[650] tracking-[-0.01em]">访问统计</h1>
+          <p className="mt-1 text-[13.5px] text-ink-2">
+            用户端访问足迹，按 IP 去重
+          </p>
+        </div>
+        <div className="flex items-center gap-0.5 rounded-lg border border-hairline-strong p-0.5">
+          {RANGES.map((r) => (
+            <button
+              key={r}
+              type="button"
+              onClick={() => setDays(r)}
+              className={cn(
+                'rounded-md px-3 py-1.5 text-[13px] transition-colors',
+                days === r
+                  ? 'bg-accent text-ground'
+                  : 'text-ink-2 hover:text-ink',
+              )}
+            >
+              {r} 天
+            </button>
+          ))}
+        </div>
+      </div>
+
+      {error && (
+        <p className="mb-4 rounded-lg border border-hairline bg-surface px-4 py-3 text-[13.5px] text-ink-2">
+          {error}
+        </p>
+      )}
+
+      <div className="mb-6 grid grid-cols-2 gap-4 lg:grid-cols-4">
+        {cards.map((c) => (
+          <div
+            key={c.label}
+            className="rounded-xl border border-hairline bg-surface p-5"
+          >
+            <div className="mb-3 flex items-center justify-between">
+              <span className="text-[12.5px] text-ink-2">{c.label}</span>
+              <c.icon className="size-[16px] text-ink-3" />
+            </div>
+            <div className="text-[26px] font-[650] tabular-nums">
+              {c.value ?? '—'}
+            </div>
+          </div>
+        ))}
+      </div>
+
+      <div className="rounded-xl border border-hairline bg-surface p-5">
+        <div className="mb-4 flex items-center justify-between">
+          <h2 className="text-[14px] font-semibold">每日访客趋势</h2>
+          <span className="font-mono text-[11.5px] text-ink-3">UV</span>
+        </div>
+        <div className="flex h-[180px] items-end gap-[3px]">
+          {series.map((s) => (
+            <div
+              key={s.date}
+              title={`${s.date} · UV ${s.uv} · PV ${s.pv}`}
+              className="flex-1 rounded-t bg-accent-soft transition-colors hover:bg-accent"
+              style={{ height: `${Math.max(2, (s.uv / maxUv) * 100)}%` }}
+            />
+          ))}
+        </div>
+        <div className="mt-2 flex justify-between font-mono text-[11px] text-ink-3">
+          <span>{series[0]?.date.slice(5)}</span>
+          <span>{series[series.length - 1]?.date.slice(5)}</span>
+        </div>
+      </div>
+    </div>
+  )
+}