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/api/cache.ts

@@ -0,0 +1,37 @@
+import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
+import type { CacheClearResult, ImageCacheStatus, TmdbCacheList } from "@umt/contracts";
+import { apiData } from "~/lib/api.ts";
+
+// C2-A 缓存管理:TMDB 缓存(条数 / 上限 / TTL / 清空)、图片代理缓存(用量 / 清空)
+
+const keys = { tmdb: ["cache", "tmdb"] as const, images: ["cache", "images"] as const };
+
+export function useTmdbCache() {
+  return useQuery({
+    queryKey: keys.tmdb,
+    queryFn: ({ signal }) => apiData<TmdbCacheList>("/cache/tmdb?limit=1", { signal }),
+  });
+}
+
+export function useClearTmdbCache() {
+  const qc = useQueryClient();
+  return useMutation({
+    mutationFn: () => apiData<CacheClearResult>("/cache/tmdb/clear", { method: "POST" }),
+    onSuccess: () => qc.invalidateQueries({ queryKey: keys.tmdb }),
+  });
+}
+
+export function useImageCache() {
+  return useQuery({
+    queryKey: keys.images,
+    queryFn: ({ signal }) => apiData<ImageCacheStatus>("/cache/images", { signal }),
+  });
+}
+
+export function useClearImageCache() {
+  const qc = useQueryClient();
+  return useMutation({
+    mutationFn: () => apiData<CacheClearResult>("/cache/images/clear", { method: "POST" }),
+    onSuccess: () => qc.invalidateQueries({ queryKey: keys.images }),
+  });
+}