[Feature] Optional on-device ML processing in the mobile app

I have searched the existing feature requests, both open and closed, to make sure this is not a duplicate request. • Yes The feature It would be useful if the Immich mobile app could optionally run ML processing locally for assets that are already present on the device. A fairly common setup is: • Immich runs on a low-power NAS or home server • photos are uploaded from a modern phone • the phone has dedicated ML hardware that is significantly more capable than the server CPU Right now, the phone uploads the original image and the server then runs face detection, smart search, etc. In some setups this is backwards from a hardware point of view: the device that already has the image may have a powerful NPU / Neural Engine, while the Immich server is running on something like an N100, Raspberry Pi or low-end NAS CPU. And this isn't just about phones having faster CPUs. Modern mobile SoCs have dedicated hardware specifically designed for ru…