Replace presigned URL string fields (logoUrl, fileUrl, ndaFileName,
etc.) with nested File references resolved through /api/files/v1/.
Update console Relay queries and e2e coverage accordingly.
Route NDA upload through filemanager.PutFile and return stable IAM
org logo URLs for consistency with the files API.
Signed-off-by: Ludovic Vielle <ludovic@probo.com>