Assistant answers now record the prompt behind them

Staff can edit and publish the prompts the assistant runs on, and a publish reaches the very next answer. Until now nothing connected the two: if answers got worse after an edit, there was no way to tell which answers had run on the old wording and which on the new.

From today every assistant answer is recorded alongside the exact set of prompt versions that composed it — each prompt file and the version live at the moment the answer was written, plus an identifier for the combination as a whole. Answers served on the shipped defaults are recorded as such, so “no published prompt yet” is distinguishable from “not recorded”.

This changes nothing about what the assistant says or who can reach it. It is the record that makes the next step possible: comparing two published versions of a prompt and seeing how answers behaved either side of the change.

One limit worth stating plainly: this applies to answers written from today onward. Answers given before it cannot be filled in after the fact, because the information exists nowhere else.