Get Folder Contents

List a folder's direct children: subfolders, files, and forms filed directly in it (not further nested).

Each item carries a type field (folder, file, or form) telling you what it is. For type: "folder" items, call this same endpoint again with that folder's id to walk further in. Forms are ordinary files under the hood (isForm: true on the underlying file) that inherit their folder/phase placement, so they appear here rather than in a separate forms listing.

Note: on this endpoint (and the phase-contents endpoint), the file's MIME/category label is named fileType instead of type, to avoid colliding with the folder/file/form discriminator. This does not affect GET /projects/{project_id}/files, where type keeps its original meaning.