feat(file-manager): suggest-name via naming engine; plan.naming source from override chain (W9-H G9)

- POST /files/suggest-name renders the effective template (entity > root >
  global) with the same variables as organize: file name segment for files,
  work/season dir segment for directories; identity_uncertain when no entity
- planImport plan.naming.templateSource/templateVersion now come from
  effectiveNaming + the registered template version (fixes the leftover
  DEFAULT_TEMPLATES reference after the naming chain landed)

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

packages/contracts/src/api.ts

@@ -1434,7 +1434,7 @@ export const Api = {
       method: "post",
       path: "/files/suggest-name",
       scope: "organize.read",
-      summary: "按命名模板生成推荐名(命名引擎未就绪时 501)",
+      summary: "按命名模板(作品 > 库根 > 全局)生成推荐名;识别不可信时 name=null + 原因",
       body: files.FilesSuggestNameRequest,
       response: files.FilesSuggestNameResult,
     }),