feat: ffprobe + TMDb scrape + HLS transcode + history/favourites/playlists

Backend
  - service/ffprobe.go: thin ffprobe wrapper, parses duration / resolution /
    codecs into a typed ProbeResult. 30s per-file timeout.
  - service/tmdb.go: minimal TMDb provider (search/movie). Disabled when no
    api key; supports tmdb_api_proxy / tmdb_image_proxy overrides for users
    behind a firewall.
  - service/scraper.go: filename cleaner (handles bracketed tags, scene
    noise tokens, year extraction), per-row + per-library enrichment with a
    4 RPS throttle and WS hub progress events. Unit-tested.
  - service/scanner.go: now invokes ffprobe per file and kicks the TMDb
    scraper in the background once a library scan finishes.
  - service/transcoder.go: per-media ffmpeg HLS job manager; outputs
    index.m3u8 + seg_NNNNN.ts under cache/hls/<id>; cancels jobs on
    shutdown; publishes 'transcode' WS events.
  - service/stream.go: serves HLS playlist (with 30s wait-for-ready) and
    .ts segments with path-traversal protection. Adds Probe() helper used
    by the admin 'reprobe' button.
  - service/image_proxy.go: cached, host-allow-listed reverse proxy for
    TMDb / Bangumi / Douban / Fanart / TheTVDB images so the SPA never
    hits a CORS or GFW issue.
  - service/playback.go: history upsert, favourites toggle, playlist CRUD
    + ordered items. RecentHistory joins with model.Media in one extra
    query so the home page can render a 'Continue Watching' row.
  - handler/streaming.go + handler/playback.go: REST endpoints for HLS,
    image proxy, scrape (one + library), reprobe, history, favourites,
    playlists.
  - handler/handler.go: registers /api/hls/:id/{index.m3u8,:seg}, /api/img,
    /api/history, /api/favourites/:id, /api/playlists/* with proper
    auth/admin guards.

Frontend
  - api/client.ts: imageURL() helper; hlsURL() endpoint; reuses the JWT in
    a query parameter for <video src> and <img src>.
  - api/playback.ts: typed helpers for history, favourites, playlists.
  - components/MediaCard.tsx: optional 'progress' prop renders a thin
    bottom progress bar, used by the new Continue Watching row.
  - pages/HomePage.tsx: two rows (Continue Watching + Recently Added);
    falls back to the empty-state hint when both are empty.
  - pages/PlayerPage.tsx: hls.js (lazy-imported) with auto-fallback to
    direct play; ?mode=hls|direct query toggle; resume position written
    every 10s while playing.
  - pages/MediaDetailPage.tsx: heart toggle + admin 'rescrape' / 'reprobe'
    buttons + dedicated 'HLS 转码播放' CTA.
  - pages/FavouritesPage.tsx, PlaylistsPage.tsx, PlaylistDetailPage.tsx:
    new screens.
  - components/Layout.tsx + App.tsx: sidebar links for Favourites and
    Playlists; routes are now lazily code-split via React.lazy + Suspense
    so the initial bundle stays at ~243 KB / 82 KB gzipped (hls.js is
    fetched only on first HLS playback).

Verified: go build, go vet, go test (incl. CleanQuery cases) all pass;
frontend tsc -b && vite build emits 9 route chunks plus a deferred hls
chunk.

web/src/components/Layout.tsx

@@ -2,7 +2,9 @@ import { useEffect, useState } from 'react'
 import { Link, NavLink, Outlet, useNavigate } from 'react-router-dom'
 import {
   Film,
+  Heart,
   Home,
+  ListMusic,
   LogOut,
   Search,
   Settings,
@@ -43,6 +45,8 @@ export function Layout() {
         <nav className="flex-1 space-y-1">
           <SidebarLink to="/" icon={<Home size={18} />} label="首页" end />
           <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" />
 
           <div className="mt-6 px-2 text-xs uppercase tracking-wider text-slate-500">
             媒体库

web/src/components/MediaCard.tsx

@@ -1,28 +1,48 @@
 import { Link } from 'react-router-dom'
 import { Film } from 'lucide-react'
 
+import { imageURL } from '../api/client'
 import type { Media } from '../types'
 
 // Compact poster tile used by every listing surface (home / library / search).
-export function MediaCard({ media }: { media: Media }) {
+//
+// Props:
+//   - media:        the Media row to render
+//   - progress:     0..1 fractional resume position (optional)
+export function MediaCard({
+  media,
+  progress,
+}: {
+  media: Media
+  progress?: number
+}) {
   return (
     <Link
       to={`/media/${media.id}`}
       className="group block overflow-hidden rounded-xl border border-white/5 bg-surface-800/60 transition hover:border-primary-400/50 hover:shadow-lg hover:shadow-primary-400/20"
     >
-      <div className="aspect-[2/3] w-full bg-surface-900">
+      <div className="relative aspect-[2/3] w-full bg-surface-900">
         {media.poster_url ? (
           <img
-            src={media.poster_url}
+            src={imageURL(media.poster_url)}
             alt={media.title}
             loading="lazy"
             className="h-full w-full object-cover transition group-hover:scale-105"
+            referrerPolicy="no-referrer"
           />
         ) : (
           <div className="flex h-full w-full items-center justify-center text-slate-600">
             <Film size={48} />
           </div>
         )}
+        {progress !== undefined && progress > 0 && progress < 1 && (
+          <div className="absolute inset-x-0 bottom-0 h-1 bg-black/60">
+            <div
+              className="h-full bg-primary-400"
+              style={{ width: `${Math.round(progress * 100)}%` }}
+            />
+          </div>
+        )}
       </div>
       <div className="px-3 py-2">
         <p className="truncate text-sm font-medium text-white">{media.title}</p>