List documents and artefacts for a child.

Authentication: JWT required RLS: User must own the child or have clinician access

Query params: source: Filter by source (all, upload, email, chat, artefacts) content_type: Filter by content type (all, documents, media). media = images + videos; documents = everything else. include_processing: Include documents with status='processing' (default: false) Staged attachments have status='processing' until chat succeeds. include_hidden: Include hidden documents (default: false) Hidden documents are kept out of Records (email artefacts, attachments of a deleted email, email documents whose ingestion failed for good). limit: Number of documents per page (1-100, default: 20) offset: Number of documents to skip (default: 0) search: Search query to filter by title, filename, summary or description