The audit found a dead mechanism twice, both times a clamp standing in for the
mechanism under test, so the technique has to survive this ticket. Not as a
script: the only cheap way to automate it is to key on source lines, that goes
stale silently, and a green audit that has quietly stopped testing anything is
this ticket's own failure mode one level up. Automating it properly would mean
decomposing compute() to make its statements separately addressable, which is a
refactor of the most safety-critical function in the repo for the benefit of
test tooling.
So it goes in as a comment block next to the checks it describes, carrying the
commit it was measured at, the thirteen figures, and the invariant with the
teeth in it: every mechanism must be noticed by at least two checks when it is
deleted, and adding a mechanism means re-running the audit. A comment cannot go
stale-green, because it never claims to be running.
Also recorded: fixtures must sit clear of every rail they are not testing,
which is the rule both misses violated; and the `python -B` / clear-pycache
discipline, with the reason (CPython invalidates on source mtime-in-seconds
plus size, so a same-second same-size rewrite reuses stale bytecode) and the
reason it casts no doubt on the figures (the error is one-directional, so every
number is a lower bound).
Figures are the lead's independent reproduction. I re-measured the one that
differed: the detector is 11 for `saturated_now = False` and 10 for the weaker
`frozen = False` form, so the table names the form.
test_control.py stays at 55 checks, all passing.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Du77usMj8XNKNFZGmUiWDa
