feat(cache): TMDB image proxy, posters, cache admin API and settings cards

GET /img/tmdb/{size}/{file} ported from MP ImageHelper / fetch_image
(sanitized cache path under DATA_DIR/cache/images, GLOBAL_IMAGE_CACHE
read switch, md5 ETag / 304, day-based cleanup job). Cache module adds
cache.sweep / cache.images_clean jobs and /cache/tmdb, /cache/images
list and clear endpoints. Library list/detail and the search palette
show posters with the neutral placeholder as fallback; metadata settings
get TMDB cache and image cache cards. Runbook docs/runbook/cache.md and
porting notes docs/porting/moviepilot-tmdb-cache.md.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

apps/web/app/components/search/command-palette.tsx

@@ -1,4 +1,4 @@
-import type { LocalMediaHit, SearchAction, TmdbCandidate } from "@umt/contracts";
+import { type LocalMediaHit, type SearchAction, type TmdbCandidate, tmdbImageUrl } from "@umt/contracts";
 import { ArrowRight, CornerDownLeft, Film, Globe, LoaderCircle, type LucideIcon, Plus, Search } from "lucide-react";
 import { type ReactNode, useEffect, useId, useMemo, useRef, useState } from "react";
 import { Link, useNavigate } from "react-router";
@@ -33,6 +33,8 @@ type Item = {
   key: string;
   group: string;
   icon: LucideIcon;
+  /** TMDB 海报路径:有则以小海报代替图标(失败回退图标) */
+  posterPath?: string | null | undefined;
   title: ReactNode;
   meta?: ReactNode;
   /** 右侧动作提示 */
@@ -216,7 +218,7 @@ function PaletteBody({ initial }: { initial: string }) {
                       i === active ? "bg-foreground/[0.06]" : "",
                     )}
                   >
-                    <it.icon className="h-4 w-4 shrink-0 text-muted-foreground" />
+                    <ItemIcon it={it} />
                     <div className="min-w-0 flex-1">
                       <div className="truncate text-sm text-foreground">{it.title}</div>
                       {it.meta ? <div className="truncate text-meta text-muted-foreground">{it.meta}</div> : null}
@@ -287,12 +289,30 @@ function localItem(h: LocalMediaHit, run: () => void): Item {
   };
 }
 
+function ItemIcon({ it }: { it: Item }) {
+  const [failed, setFailed] = useState(false);
+  const src = failed ? null : tmdbImageUrl(it.posterPath, "w92");
+  if (src) {
+    return (
+      <img
+        src={src}
+        alt=""
+        loading="lazy"
+        onError={() => setFailed(true)}
+        className="h-9 w-6 shrink-0 rounded-tight border border-border object-cover"
+      />
+    );
+  }
+  return <it.icon className="h-4 w-4 shrink-0 text-muted-foreground" />;
+}
+
 function tmdbItem(c: TmdbCandidate, view: () => void, subscribe: (c: TmdbCandidate) => void): Item {
   const local = !!c.localEntityId;
   return {
     key: `tmdb-${c.entityType}-${c.externalId}`,
     group: "TMDB",
     icon: local ? Globe : Plus,
+    posterPath: c.posterPath,
     title: (
       <span>
         {c.title}