Protocol reverse engineered from real captures and analysis in
https://github.com/merbanan/rtl_433/issues/2133 and the earlier
https://groups.google.com/g/rtl_433/c/VJSPl7h0848 thread, re-derived from
scratch and cross-checked against 18 real messages from 3 independent
devices (ID, level, and battery-low all confirmed; no whole-message
checksum found). RF timing (short_width/long_width) is a best estimate
from real captures in both threads, not live-verified end-to-end -- see
file header.
928817e0ef