VSC extension human checkpoint should send dirty files before AI checkpoint to avoid races #221
Description
Very occasionally, the human checkpoint could read files after Copilot has already started editing the file with AI changes.
This could happen because the human checkpoint is technically async since Copilot doesn't actually have real 'hooks' support. I could only replicate this once with a very fast model, but it is better design to make sure that we pass the content of the file that's about to be edited in the human checkpoint just to eliminate this potential edge case going forward.