feat(cache): 通用缓存按区统计与清空接口

GET /cache/regions 列出 kv_cache 各区的未过期条数、已过期条数、占用字节、最近写入;
POST /cache/regions/{region}/clear 清空一个区(admin)。contracts 加区名中文映射
cacheRegionLabel,web 加对应 hooks。

Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01Cxwgnn2pbzQ7rXv3rq7fei

packages/contracts/src/api/platform.ts

@@ -95,6 +95,21 @@ export const platformApi = {
       summary: "清空图片代理缓存",
       response: cache.CacheClearResult,
     }),
+    regions: ep({
+      method: "get",
+      path: "/cache/regions",
+      scope: "admin",
+      summary: "通用缓存（kv_cache）按区统计：条目数、已过期数、占用字节、最近写入",
+      response: cache.CacheRegionList,
+    }),
+    regionClear: ep({
+      method: "post",
+      path: "/cache/regions/{region}/clear",
+      scope: "admin",
+      summary: "清空通用缓存的一个区",
+      params: cache.CacheRegionParam,
+      response: cache.CacheClearResult,
+    }),
   },
 
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