Feature request: option to use caption for alt text

When adding a photo from the camera roll, if the photo has a caption, show the caption and provide a "copy to alt text" button, possibly before or after the 🤖 generate description button.

I'm pretty sure the APIs are there to do it, though I haven't written a test app yet. (also, LMK if you'd like me to take a stab at it, assuming that local builds aren't prohibitively difficult to set up)

use case: I have memes that I use a lot, and I've entered their alt-text as a caption in my photo library -- it'd be super-handy to have

bonus round: option to edit / add the caption/alt-text from within IceCubes

Start by locating the camera-roll photo attachment flow and the existing 🤖 “generate description” action in IceCubesApp. Check how photo captions and alt text are exposed by the relevant APIs, then define done as showing a caption when available and allowing it to be copied into alt text; treat editing captions as separate bonus scope.