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/src/modules/index.ts

@@ -1,6 +1,7 @@
 import { acquisitionOrganizeModule } from "./acquisition-organize/index.ts";
 import { agentModule } from "./agent/index.ts";
 import { authSettingsModule } from "./auth-settings/index.ts";
+import { fileManagerModule } from "./file-manager/index.ts";
 import { sourcesIdentityModule } from "./sources-identity/index.ts";
 import type { ServerModule } from "./types.ts";
 
@@ -15,4 +16,5 @@ export const SERVER_MODULES: readonly ServerModule[] = [
   sourcesIdentityModule,
   acquisitionOrganizeModule,
   agentModule,
+  fileManagerModule,
 ];