feat(server): W5-A file manager module (/files)

Roots/list/stat with inline business status, path guard (realpath within
registered roots, symlink escape, offline root 503), mkdir/rename syncing
asset_location and path_binding revisions, two-phase move/copy/organize
(planId + source facts), trash with reference checks and purgeTrash task,
identify/probe/scrape, audit + idempotency keys. Runbook docs/runbook/files.md.

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

apps/server/test/modules.test.ts

@@ -43,12 +43,13 @@ const pingModule: ServerModule = {
 };
 
 describe("ServerModule 骨架", () => {
-  it("清单里是四个 W2 模块,名字唯一", () => {
+  it("清单里是四个 W2 模块 + 文件管理,名字唯一", () => {
     expect(SERVER_MODULES.map((m) => m.name)).toEqual([
       "auth-settings",
       "sources-identity",
       "acquisition-organize",
       "agent",
+      "file-manager",
     ]);
   });