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/components/Layout.tsx

@@ -3,14 +3,17 @@ import { Link, NavLink, Outlet, useNavigate } from 'react-router-dom'
 import {
   Activity,
   CloudDownload,
+  Compass,
   Film,
   Heart,
   Home,
+  ListChecks,
   ListMusic,
   LogOut,
   Rss,
   Search,
   Settings,
+  Trash2,
   Library as LibraryIcon,
   User as UserIcon,
 } from 'lucide-react'
@@ -48,6 +51,7 @@ export function Layout() {
 
         <nav className="flex-1 space-y-1 overflow-y-auto pr-1">
           <SidebarLink to="/" icon={<Home size={18} />} label="首页" end />
+          <SidebarLink to="/discover" icon={<Compass size={18} />} label="发现" />
           <SidebarLink to="/search" icon={<Search size={18} />} label="搜索" />
           <SidebarLink to="/favourites" icon={<Heart size={18} />} label="收藏" />
           <SidebarLink to="/playlists" icon={<ListMusic size={18} />} label="播放列表" />
@@ -83,7 +87,9 @@ export function Layout() {
               <div className="mt-6 px-2 text-xs uppercase tracking-wider text-slate-500">
                 管理
               </div>
+              <SidebarLink to="/tasks" icon={<ListChecks size={18} />} label="实时任务" />
               <SidebarLink to="/stats" icon={<Activity size={18} />} label="运行状态" />
+              <SidebarLink to="/recycle" icon={<Trash2 size={18} />} label="回收站" />
               <SidebarLink to="/admin" icon={<Settings size={18} />} label="管理后台" />
             </>
           )}