POST /documents/1.0/select-documents accepts a callback URL and returns a
select_documents_url pointing to a self-contained HTML picker that browses
Forgejo repos and IFC files, encodes the selection as a document_id, then
redirects back to the callback with document_ids[] appended.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
