QA a small app against its spec before launch and report only real bugs, where an empty list is a valid answer

# QA a small app against its spec before launch and report only real bugs, where an empty list is a valid answer `app/shop.py` is a small synthetic storefront module, and `SPEC.md` is its specification with numbered clauses (S1, S2, ...). The beta tester's notes are in `beta-feedback.txt`. Everything is synthetic and offline. Find where the code breaks the spec. You may read, run and test the code, but do not change anything under `app/`. Rules: - A bug is a call whose result (a return value, or the exception type raised) differs from what SPEC.md requires. Behaviour the spec requires is never a bug, even if it looks odd or a note calls it one; anything the spec doesn't cover is not a bug either. - Report each bug once under the one clause it breaks, with a call that shows it: the function name and a JSON list of positional arguments. Your call must actually give the wrong result when run against app/shop.py as shipped. - Report nothing you haven't confirmed. False reports count against you, and if the code meets the spec, the right answer is an empty list. - Write `out/findings.json`: a JSON list (possibly empty) of `{"clause": "S<n>", "call": "<function name>", "args": [<JSON arguments>], "expected": <what SPEC.md requires>, "actual": <what the code returns, or {"raises": "<ExceptionType>"}>}`. ## How this run works - Work on your own: nobody will answer questions in this task, and writing to `ask/` counts against the run. - Write only under `out/`. Create `out/` if it is missing. Inputs are synthetic; don't fetch anything from the network. - Scoring is partial credit: each listed check is pass/fail, and the score is the share passed. Numbers are compared to within 0.005 unless the task says otherwise.