feat(documents): importer for organized S3/filesystem buckets

One-shot script that walks an existing organized bucket tree, builds
matching document_folders rows mirroring the path, then inserts
documents + files rows pointing at the existing storage keys verbatim
— no path rewrite. For migrating from a legacy MinIO bucket whose
folder structure is already the source of truth.

Idempotency:
  • Folders: sibling-name unique index swallows duplicate creates;
    we reuse the row on ConflictError.
  • Documents: skipped when (port_id, fileStoragePath) already exists.

Adds StorageBackend.listByPrefix (recursive readdir on filesystem;
listObjectsV2 stream-drain on s3) — the first one-shot caller, not
a hot path. Pure parseImportPath helper extracted to its own module
and unit-tested for trailing slashes, empty intermediate segments,
prefix mismatch, and special-character folder names (8 tests).

Audit log per imported doc carries source='organized-bucket-importer',
storageKey, and folderSegments so the documents inspector can filter
on imports later.

CLI:
  pnpm tsx scripts/import-organized-documents.ts \\
      --port-slug <slug> \\
      --bucket-prefix "legacy-imports/" \\
      (--dry-run | --apply) [--uploaded-by <userId>]

Folds in Prettier post-hook drift on documents.service.ts +
download handler — same lint-staged formatting the earlier commits
already absorbed.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/app/api/v1/documents/[id]/download/[...slug]/handlers.ts

@@ -73,11 +73,7 @@ export const downloadHandler: RouteHandler<DownloadParams> = async (_req, ctx, p
   }
 };
 
-function buildExpectedSlug(
-  folderId: string | null,
-  filename: string,
-  tree: FolderNode[],
-): string {
+function buildExpectedSlug(folderId: string | null, filename: string, tree: FolderNode[]): string {
   const segments: string[] = [];
   if (folderId) {
     const path = findFolderPath(tree, folderId);