Second demo fixture (public-sample shape) to complement the all-rules
pump_station.st: a timed pedestrian-crossing state machine adapted from
the OpenPLC traffic-light example, extended with a SCADA/Modbus uplink and
a maintenance override. Mostly sound control logic with three planted,
field-realistic defects (hardcoded SCADA password, cleartext Modbus master,
maintenance mode that drops the pedestrian safety permit).
The regression test asserts the scanner surfaces those defects while staying
quiet on the guarded duty-cycle division and the JMP-free CASE machine —
demonstrating low false positives on real-world-shaped code.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
