The relay must detect image attachments in BlueBubbles message
objects
An image attachment is defined as: mimeType starts with
image/ (e.g., image/jpeg,
image/png, image/heic)
The relay must extract attachment metadata: GUID, mimeType,
transferName, and a retrievable representation of the image data
Non-image attachments (video, audio, documents, vCards, locations)
must be ignored for this feature (show a generic placeholder: “[Video]”,
“[Audio]”, “[File]”)