A pull red only on a test its diff does not touch gets one fresh re-check before the decider may park it #7630

Flow. #7552 was parked twice on reds in tests its change never reached: the People-screen verify test, which is order-dependent (#7599). Each park cost the owner's ask a day.

Done when:

• [ ] When a pull's check fails, and every failing test file is outside the files the impact map (src/checks/impact.ts) links to the pull's diff, the forge runs the check once more on the same head before the decider is asked. The run says re-checked: red outside the diff (<file>).
• [ ] A second red on that head goes to the decider as today.
• [ ] A test proves both paths: one re-check then green lands; two reds reach the decider. A red inside the diff gets no re-check.

Files: src/checks/recheck.ts or src/checks/again.ts (whichever owns automatic re-checks today), a test. Risk: a loop. The rule is one fresh re-check per head, recorded.

Owner's conductor: a one-red park is removed on main (34bea24a): every failed check goes back to its builder, and only the two-try limit parks. Please rebase pull #7682 onto that and keep only what still adds value: one fresh re-check for a red outside the diff before a try is spent.