List Project Folders

Retrieve the top level of a project's Docs tab: workflow phases, plus any real doc folders that sit at the project root (not nested in another folder or scoped to a phase). Each item carries a `type` field (`phase` or `folder`) telling you what it is and, for folders, matches the shape of `GET /folders/{folder_id}`. **Behavior change:** this endpoint used to return every real folder flat, including ones nested under another folder or scoped to a phase. It now returns root-level folders only, alongside phase rows, matching what the UI shows at the top of the Docs tab. To see what's inside a phase or folder, use `GET /phases/{phase_instance_id}/contents` or `GET /folders/{folder_id}/contents`. Pagination (`page`/`page_size`) applies only to the folder half of the results — phase rows are returned unpaginated (bounded by the project's workflow, not user-created volume). Pass `include_archived=true` to include archived root folders (default `false`); this doesn't affect phase rows.