feat: hwaccel + Fanart/TheTVDB + AI + Discover + NFO + Tasks + Recycle bin

Backend
  - service/transcoder.go: encoder selector (software / nvenc / qsv /
    vaapi) with proper hwaccel + scale_* filters per encoder; configurable
    bitrate/preset/height/segment-seconds via transcoder.* config; new
    Active() snapshot + ActiveJob struct for the Tasks panel; unit-tested
    via buildFFmpegArgs(...).
  - service/thetvdb.go: TheTVDB v4 provider — login() caches the JWT for
    24h, SearchSeries() returns Match struct.
  - service/fanart.go: Fanart.tv provider — high-res movie artwork keyed
    by TMDb id; used to upgrade poster/backdrop after a successful match.
  - service/scraper.go: provider chain reworked — anime → Bangumi, tv →
    TheTVDB, default → TMDb, with optional Fanart upgrade post-match.
  - service/discover.go: TMDb /trending/movie/day + /movie/popular for
    the Discover rail.
  - service/ai.go: OpenAI-compatible client. SmartSearch() turns a free-
    form query into a structured SearchIntent JSON; Recommend() emits a
    short list of titles given the user's history. Disabled when
    ai.api_key is empty.
  - service/nfo.go: per-movie .nfo writer (Kodi/Jellyfin schema) +
    library-scope batch exporter.
  - service/media.go: SoftDelete / Restore / Purge / ListRecycleBin
    helpers backed by gorm Unscoped().
  - service/service.go: container wires Fanart, TheTVDB, Discover, AI,
    NFO; everything still tears down cleanly via Close().
  - config: new transcoder.* section (encoder, preset, video_bitrate,
    max_rate, buf_size, max_height, segment_seconds) with sensible
    defaults.

Handlers / routes
  - new files: discover.go, recycle.go, nfo.go, ai.go, tasks.go.
  - registers GET /tasks, /discover/{trending,popular},
    /ai/{status,search,recommend}; admin-only GET /recycle and
    DELETE/POST /media/:id (soft delete / restore / purge); admin-only
    POST /media/:id/nfo and /libraries/:id/nfo.

Frontend
  - new pages: DiscoverPage, TasksPage, RecycleBinPage; SearchPage gains
    an optional AI smart-search toggle that calls /api/ai/search.
  - MediaDetailPage gains admin actions for 导出 NFO and 移至回收站.
  - new api/ helpers: ai.ts, discover.ts, recycle.ts, tasks.ts.
  - App.tsx routes /discover, /tasks, /recycle (last two admin-only).
  - Layout sidebar groups now include Discover + Tasks + Recycle Bin.

Docker / config
  - Dockerfile: adds intel-media-driver / libva-utils / mesa-va-gallium
    so QSV + VAAPI work out of the box on Intel iGPUs.
  - docker-compose.yml: documents devices + group_add + nvidia runtime
    overrides for hardware transcoding.

Verified: go build, go vet, go test (incl. new TestBuildFFmpegArgs across
software / nvenc / qsv / vaapi encoder profiles); tsc -b && vite build
emits 22 route chunks plus the deferred hls chunk; main bundle 248 KB /
83 KB gzipped.

web/src/pages/TasksPage.tsx

@@ -0,0 +1,125 @@
+import { useEffect, useState } from 'react'
+import { Activity } from 'lucide-react'
+
+import { tasksAPI, type TasksSnapshot } from '../api/tasks'
+
+function fmtBytes(n: number): string {
+  if (!n || n <= 0) return '0 B'
+  const u = ['B', 'KB', 'MB', 'GB', 'TB']
+  let v = n
+  let i = 0
+  while (v >= 1024 && i < u.length - 1) {
+    v /= 1024
+    i++
+  }
+  return `${v.toFixed(2)} ${u[i]}`
+}
+
+// TasksPage shows everything the backend is doing right now: ffmpeg
+// transcodes + qBittorrent downloads. Refreshes every 3 s.
+export function TasksPage() {
+  const [snap, setSnap] = useState<TasksSnapshot | null>(null)
+
+  useEffect(() => {
+    let cancelled = false
+    const tick = () =>
+      tasksAPI.snapshot().then((s) => {
+        if (!cancelled) setSnap(s)
+      })
+    void tick()
+    const id = window.setInterval(tick, 3_000)
+    return () => {
+      cancelled = true
+      window.clearInterval(id)
+    }
+  }, [])
+
+  if (!snap) return <p className="text-slate-500">加载中…</p>
+
+  const torrents = snap.torrents ?? []
+
+  return (
+    <div className="space-y-8">
+      <header className="flex items-center gap-3">
+        <Activity className="h-6 w-6 text-primary-400" />
+        <h1 className="font-display text-3xl font-bold text-white">实时任务</h1>
+      </header>
+
+      <section className="glass-panel">
+        <h2 className="mb-3 font-display text-lg font-semibold text-white">转码任务</h2>
+        {snap.transcodes.length === 0 && <p className="text-slate-500">暂无运行中转码。</p>}
+        {snap.transcodes.length > 0 && (
+          <table className="w-full text-left text-sm">
+            <thead className="text-xs uppercase tracking-wider text-slate-500">
+              <tr>
+                <th className="py-2">媒体 ID</th>
+                <th>编码器</th>
+                <th>开始时间</th>
+                <th>就绪</th>
+              </tr>
+            </thead>
+            <tbody>
+              {snap.transcodes.map((t) => (
+                <tr key={t.media_id} className="border-t border-white/5">
+                  <td className="py-2 font-mono text-xs text-white">{t.media_id}</td>
+                  <td className="text-slate-300">{t.encoder || 'libx264'}</td>
+                  <td className="text-slate-300">{new Date(t.started_at).toLocaleTimeString()}</td>
+                  <td>
+                    {t.playlist_ok ? (
+                      <span className="rounded border border-emerald-400/40 px-1.5 py-0.5 text-xs text-emerald-400">
+                        ready
+                      </span>
+                    ) : (
+                      <span className="rounded border border-yellow-400/40 px-1.5 py-0.5 text-xs text-yellow-400">
+                        starting
+                      </span>
+                    )}
+                  </td>
+                </tr>
+              ))}
+            </tbody>
+          </table>
+        )}
+      </section>
+
+      <section className="glass-panel">
+        <h2 className="mb-3 font-display text-lg font-semibold text-white">下载任务</h2>
+        {torrents.length === 0 && <p className="text-slate-500">暂无运行中下载。</p>}
+        {torrents.length > 0 && (
+          <table className="w-full text-left text-sm">
+            <thead className="text-xs uppercase tracking-wider text-slate-500">
+              <tr>
+                <th className="py-2">名称</th>
+                <th>状态</th>
+                <th>进度</th>
+                <th>体积</th>
+              </tr>
+            </thead>
+            <tbody>
+              {torrents.map((t) => (
+                <tr key={t.hash} className="border-t border-white/5 align-top">
+                  <td className="max-w-md truncate py-2 text-white" title={t.name}>
+                    {t.name}
+                  </td>
+                  <td className="text-slate-300">{t.state}</td>
+                  <td className="text-slate-300">
+                    <div className="flex items-center gap-2">
+                      <div className="h-1 w-24 overflow-hidden rounded bg-white/10">
+                        <div
+                          className="h-full bg-primary-400"
+                          style={{ width: `${Math.round(t.progress * 100)}%` }}
+                        />
+                      </div>
+                      {(t.progress * 100).toFixed(1)}%
+                    </div>
+                  </td>
+                  <td className="text-slate-300">{fmtBytes(t.size)}</td>
+                </tr>
+              ))}
+            </tbody>
+          </table>
+        )}
+      </section>
+    </div>
+  )
+}