Fix Receipts — state the goal and its probes, get a verified receipt

Notes & tips

• Preview first. The preview costs nothing and catches malformed probes before a run.
• Prefer plural probes that are distinct from the fix target — a target probe plus a suite probe plus a scope constraint is the shape that actually proves something.
• The receipt distinguishes "changed nothing and the conditions already held" from "fixed and verified". If you see the former, check that your goal described a real gap.
• Probe subprocesses run with bytecode and pytest-cache writes disabled so their own artifacts are never mistaken for the fix's changes.