photo edit is saved where?

The phone doesn't exactly save an edited copy of the picture-- it saves the steps you went through to edit it! So when you click on the picture it reconstructs the edits. This saves having two copies of the picture, and it means the original unedited photo is always available if you want to change what you did. (You may remember seeing the "Revert" button in edit mode.) There are thumbnails and such saved for fast browsing, but if you want to print the edited picture, for instance, it's just created on the fly. Really cool!

If you really, really want to do that, then you'd need to export the edited version; delete (or hide) the original; and import the saved edited version. There is a "Duplicate" option, but it duplicates the original with the editing instructions. Personally, I'm never sure enough that the editing I've done is what I will want to see in 10 years, so I don't delete originals.

Well, I don't do this on my phone, so I'm not sure of the best way-- I would do it on the computer. But, I tried sharing to Notes and then, in Notes, saving the picture in Photos, and the edited and cropped version was what was imported. You might be able to save several at once, and import all together-- I didn't try that.