Closes the coolant/jam investigation. BT_AF_PERIOD pulses the trigger every <sec>s so
a slower-than-max fire rate can be tested; afc_dump.py reads the AFC100 record raw from
BTL4.RES. Both confirm the QA report is FAITHFULLY reproduced (see KB).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>