Your phone gets the delete key
The signed-in API now lets the app delete your account, taking your commits and approved devices with it. One signed request and you're gone.
You tap Delete account in the app and confirm. The server answers 204 with no body. The next call signed with that same key comes back 401, device_not_approved, and your account is gone.
Credit goes to simonhamp, who wired the app's delete button to the same routine the web's Delete account uses. The request has no body. The signature is the only credential. It erases your top-level commits and everything under them, recalculates the hot scores of commits you starred or replied to, and keeps replies that other people answered as authorless tombstones so the threads below them survive. Deleting the account takes every approved device with it.
One catch. The server never asks twice. The request accepts nothing and checks nothing beyond the signature, so the app's dialog is the only guard. Any signed delete that lands wipes the account on the spot, with no password and no undo.