prove-it

Don't say a task is done until you can prove it. Triggers right before you'd report work finished (or on /prove-it). For every claim you're about to make — "it works", "tests pass", "the bug is fixed" — it makes you show evidence: run it and paste the real output, or cite the exact file:line. No proof, no "done"; what you couldn't verify, you say so plainly.