[Feature] Merge Faces from Metadata with detected faces

I have searched the existing feature requests to make sure this is not a duplicate request.

• Yes

The feature

In immich implemented reading face metadata from files.

These faces show up in the people view, etc but they are often duplicated with immich's own detected faces. When there is a significant overlap with an ML detected face immich should merge the detected faces with the one provided by metadata (and ideally their linked groups too).

My observation is that most detected face bounding boxes detected by digikam very closely match the size and shape of the bounding boxes generated by immich for the same faces so this would be very useful for portability.

Platform

• Server
• Web
• Mobile