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]>

packages/contracts/src/api.ts

@@ -3,6 +3,7 @@ import * as agent from "./agent.ts";
 import * as assets from "./assets.ts";
 import * as auth from "./auth.ts";
 import * as browser from "./browser.ts";
+import * as cache from "./cache.ts";
 import { CapabilityDescriptor, KnownCapabilityId } from "./capability.ts";
 import { type ApiScope, CursorQuery, cursorPage, HealthStatus, Id, IdParam } from "./common.ts";
 import * as content from "./content.ts";
@@ -1611,6 +1612,39 @@ export const Api = {
     }),
   },
 
+  // ── 缓存(C2-A,docs/runbook/cache.md) ──
+  cache: {
+    tmdb: ep({
+      method: "get",
+      path: "/cache/tmdb",
+      scope: "admin",
+      summary: "TMDB 缓存条目（请求响应与识别结果：键、过期时间、大小）与上限 / TTL",
+      query: cache.TmdbCacheQuery,
+      response: cache.TmdbCacheList,
+    }),
+    tmdbClear: ep({
+      method: "post",
+      path: "/cache/tmdb/clear",
+      scope: "admin",
+      summary: "清空 TMDB 缓存（请求响应与识别结果）",
+      response: cache.CacheClearResult,
+    }),
+    images: ep({
+      method: "get",
+      path: "/cache/images",
+      scope: "admin",
+      summary: "图片代理缓存用量",
+      response: cache.ImageCacheStatus,
+    }),
+    imagesClear: ep({
+      method: "post",
+      path: "/cache/images/clear",
+      scope: "admin",
+      summary: "清空图片代理缓存",
+      response: cache.CacheClearResult,
+    }),
+  },
+
   // ── 设置 ──
   settings: {
     get: ep({ method: "get", path: "/settings", scope: "read", summary: "全局设置", response: GlobalSettings }),