New saves go into the patient's Cloud Storage folder under category subfolders
(Eligibility/Claims/PreAuth/Claim Status/Attachments) via a new
storage.savePdfToCloudStorage helper, instead of the legacy PdfGroup/PdfFile
Postgres blob tables. Old records and their read paths are left untouched for
backward compatibility; PDF list/content/delete endpoints and viewers now
transparently handle both legacy numeric ids and new "cloud:<id>" ids.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>