The app gets a vote
Signed-in requests can now vote on a commit's poll, and the answer hands back the whole commit with the counts already filled in.

You tap a poll on your phone, choose Spaces, and press Vote. No reload, no spinner limbo. The same commit comes back down the wire, and the poll underneath it now has numbers. Two people picked Tabs, you picked Spaces, and the bars read 67 and 33.
Credit goes to simonhamp, who wired the app to the same vote the web's Vote button casts. Post an option's id to the poll's votes endpoint and you get the commit as its page shows it, so your client can redraw the whole card in one pass. The request carries a signed key, not a browser session. Under the hood it reuses the web's rules. The rules are one vote row per person, an insert that quietly ignores a duplicate, and percentages rounded to whole numbers.
One catch. The vote is final. Send a second one and the API answers 422 with "You have already voted on this poll," and there is no route yet to take a vote back or switch to the other option. Pick carefully.