The event's whole communications timeline: SMS, voice and e-mail rows, oldest first.

RESPONSE SHAPE (this route is response_model=list[dict], a legacy escape hatch): each row is NotificationLog.to_dict_frontend() PLUS attachments. THAT KEY IS PRESENT ON EVERY ROW OF THIS RESPONSE and is null on the voice, e-mail and manually-logged ones — uniform within a response, absent from unrelated responses. Each entry is {kind, url, content_type}; url is a presigned GET valid 3600s, minted for this read and null if presigning failed (the row is still returned). null, never [], when a row carried nothing.