Returns base64-encoded radiology report PDF, DICOM imaging data, and invoice for a single
order visible to the authenticated user's group.

Provide one lookup method:

• order_id — order UUID
• reference_id — accession / reference ID on the order
• patient_name + date_of_birth + study_description — patient and study description
  (study description is resolved via the Translation table, same as inbound image matching)

report, dicom, and invoice are omitted (null) when not available for the order.
DICOM is returned as a base64-encoded zip when fetched live from Ambra storage.
Invoice is loaded from the parent appointment attachment.