feat: downloads, RSS, subtitles, Bangumi, watcher, stats, profile, audit

Backend
  - service/bangumi.go: Bangumi (bgm.tv) scraper for anime libraries.
  - service/episode_parser.go: SxxExx / NxE / EPxx / 第NN集 parser with
    unit tests; consumed by the scanner for tv/anime libraries.
  - service/scraper.go: provider chain orchestrator picks Bangumi for
    anime libraries (TMDb fallback), TMDb for everything else; emits
    'no_match' rows so we don't retry forever; AnyEnabled() for the
    scanner kick.
  - service/scanner.go: writes season/episode numbers for tv/anime libs
    and reports a 'probed' counter alongside 'added'.
  - service/transcoder.go (existing): unchanged, stays per-media.
  - service/subtitle.go: discovers external subtitles next to the source
    file (.srt/.vtt/.ass/.ssa) and converts SRT/ASS to WebVTT on the fly.
  - service/qbittorrent.go: thread-safe qBittorrent v2 Web UI client
    (login / add / list / delete) with cookie-jar reuse.
  - service/downloads.go: persists download tasks, reads runtime
    qbittorrent.* settings, polls /torrents/info every 5 s and pushes
    the result to WS subscribers ('download' topic).
  - service/subscription.go: 10-minute RSS poller with regex filter,
    GUID dedup persisted in the settings table, and 'subscription' WS
    events on enqueue.
  - service/watcher.go: fsnotify watcher with 5 s coalescing debouncer
    that triggers per-library rescans on create/rename/remove.
  - service/stats.go: dashboard snapshot — totals, recently added,
    gopsutil-driven CPU/mem/disk readings.
  - service/profile.go: non-credential profile patch + admin role mutator.
  - service/audit.go: best-effort writer for the access_logs table.
  - service/service.go: container wires every new service; Boot() spins
    up watcher / downloads poller / subscription scheduler; Close()
    tears them down on graceful shutdown.

Handlers
  - new files: downloads.go, subscriptions.go, subtitles.go, series.go,
    stats.go, profile.go, util.go.
  - handler.go: registers PATCH /me, /libraries/:id/seasons,
    /media/:id/subtitles, /subtitles/:id, /downloads*, /subscriptions*,
    /stats, /admin/users/:id/role.
  - auth.go / media.go: write audit rows for login + library CRUD and
    refresh the watcher when libraries change.

Frontend
  - api: new helpers for downloads, subscriptions, profile, series, stats,
    subtitles; library helper gained scrape().
  - hooks/useWebSocket.ts: shared connection with 3 s reconnect.
  - components/GlobalEvents.tsx: surfaces scan / scrape / subscription
    completion as toasts (mounted at app root).
  - pages: Library now switches to a season-grouped layout for tv/anime
    libraries; Player attaches WebVTT <track> elements; new pages for
    Downloads (live torrent table), Subscriptions, Profile, Stats.
  - components/Layout.tsx + App.tsx: sidebar groups (媒体库 / 自动化 /
    账号 / 管理) and routes for the new pages; /stats and /admin remain
    admin-only.
  - types/index.ts: new types — Subscription, DownloadTask, QBitTorrent,
    Hardware, StatsSnapshot.

Verified: go build, go vet, go test (incl. ParseEpisode + srtToVTT +
stripASSTags) all pass; tsc -b && vite build emits 17 route chunks plus
the deferred hls chunk; main bundle 247 KB / 83 KB gzipped.

web/src/pages/StatsPage.tsx

@@ -0,0 +1,137 @@
+import { useEffect, useState } from 'react'
+import { Activity, Cpu, Database, Film, HardDrive, Users } from 'lucide-react'
+
+import { statsAPI } from '../api/stats'
+import { MediaCard } from '../components/MediaCard'
+import type { StatsSnapshot } from '../types'
+
+// fmtBytes is a tiny helper shared by the dashboard cards.
+function fmtBytes(n: number): string {
+  if (!n || n <= 0) return '—'
+  const u = ['B', 'KB', 'MB', 'GB', 'TB', 'PB']
+  let v = n
+  let i = 0
+  while (v >= 1024 && i < u.length - 1) {
+    v /= 1024
+    i++
+  }
+  return `${v.toFixed(2)} ${u[i]}`
+}
+
+function fmtHours(seconds: number): string {
+  if (!seconds || seconds <= 0) return '—'
+  const h = Math.floor(seconds / 3600)
+  return `${h.toLocaleString()} h`
+}
+
+// StatsPage renders the operator dashboard. Refreshes every 10 s.
+export function StatsPage() {
+  const [snap, setSnap] = useState<StatsSnapshot | null>(null)
+  const [loading, setLoading] = useState(true)
+
+  useEffect(() => {
+    let cancelled = false
+    const tick = () =>
+      statsAPI.snapshot().then((s) => {
+        if (!cancelled) setSnap(s)
+      })
+    tick().finally(() => setLoading(false))
+    const id = window.setInterval(tick, 10_000)
+    return () => {
+      cancelled = true
+      window.clearInterval(id)
+    }
+  }, [])
+
+  if (loading) return <p className="text-slate-500">加载中…</p>
+  if (!snap) return <p className="text-slate-500">无法获取统计数据</p>
+
+  const memPct =
+    snap.hardware.memory_total > 0
+      ? (snap.hardware.memory_used / snap.hardware.memory_total) * 100
+      : 0
+  const diskPct =
+    snap.hardware.disk_total > 0
+      ? (snap.hardware.disk_used / snap.hardware.disk_total) * 100
+      : 0
+
+  return (
+    <div className="space-y-8">
+      <header>
+        <h1 className="font-display text-3xl font-bold text-white">运行状态</h1>
+        <p className="text-sm text-slate-400">
+          快照时间:{new Date(snap.generated_at).toLocaleString()}
+        </p>
+      </header>
+
+      <section className="grid gap-4 sm:grid-cols-2 md:grid-cols-3 lg:grid-cols-4">
+        <Tile icon={<Database size={20} />} label="媒体库" value={snap.libraries.toLocaleString()} />
+        <Tile icon={<Film size={20} />} label="媒体总数" value={snap.media_count.toLocaleString()} />
+        <Tile icon={<Users size={20} />} label="用户" value={snap.users_count.toLocaleString()} />
+        <Tile icon={<HardDrive size={20} />} label="入库容量" value={fmtBytes(snap.total_size_bytes)} />
+        <Tile icon={<Activity size={20} />} label="累计时长" value={fmtHours(snap.total_seconds)} />
+        <Tile icon={<Cpu size={20} />} label="CPU 占用" value={`${snap.hardware.cpu_percent.toFixed(1)}%`} />
+        <Tile icon={<Cpu size={20} />} label="内存占用" value={`${memPct.toFixed(1)}%`} />
+        <Tile icon={<HardDrive size={20} />} label="数据盘占用" value={`${diskPct.toFixed(1)}%`} />
+      </section>
+
+      <section className="space-y-3">
+        <h2 className="font-display text-xl font-semibold text-white">系统</h2>
+        <div className="glass-panel grid gap-2 text-sm">
+          <Row label="Go 运行时" value={snap.hardware.go_version} />
+          <Row label="Goroutines" value={snap.hardware.goroutines.toLocaleString()} />
+          <Row
+            label="内存"
+            value={`${fmtBytes(snap.hardware.memory_used)} / ${fmtBytes(snap.hardware.memory_total)}`}
+          />
+          <Row
+            label="数据盘"
+            value={`${fmtBytes(snap.hardware.disk_used)} / ${fmtBytes(snap.hardware.disk_total)}`}
+          />
+        </div>
+      </section>
+
+      {snap.recently_added.length > 0 && (
+        <section className="space-y-3">
+          <h2 className="font-display text-xl font-semibold text-white">最近入库</h2>
+          <div className="grid grid-cols-2 gap-4 sm:grid-cols-3 md:grid-cols-4 lg:grid-cols-5 xl:grid-cols-6">
+            {snap.recently_added.map((m) => (
+              <MediaCard key={m.id} media={m} />
+            ))}
+          </div>
+        </section>
+      )}
+    </div>
+  )
+}
+
+function Tile({
+  icon,
+  label,
+  value,
+}: {
+  icon: React.ReactNode
+  label: string
+  value: string
+}) {
+  return (
+    <div className="glass-panel flex items-center gap-3 !p-4">
+      <div className="rounded-lg border border-primary-400/40 bg-primary-400/10 p-2 text-primary-400">
+        {icon}
+      </div>
+      <div>
+        <p className="text-xs uppercase tracking-wider text-slate-500">{label}</p>
+        <p className="font-display text-lg font-semibold text-white">{value}</p>
+      </div>
+    </div>
+  )
+}
+
+function Row({ label, value }: { label: string; value: string }) {
+  return (
+    <div className="flex items-center justify-between border-b border-white/5 pb-1 text-sm last:border-0">
+      <span className="text-slate-400">{label}</span>
+      <span className="font-mono text-white">{value}</span>
+    </div>
+  )
+}