Code-review followups on 4b31f01:
- beforeEach now scopes the documentFolders cleanup to the test port
via .where(eq(documentFolders.portId, portId)) so parallel suites
don't wipe each other's fixtures.
- Cross-port parent guard message changed from "Parent folder not
found in this port" (read like a 404) to "Invalid parent folder"
to match the ValidationError type that already maps to 400.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>