custom_components/houseplan/junction_limits.py repeats П1-П4 for the write
barrier in websocket_api, counting per rule so an inherited violation still
round-trips, and raises JunctionLimitError with the stable code
junction_limit_<rule>.
П5 is deliberately not mirrored — it judges the rendered wall bodies, and a
second mitre/inset pipeline in Python would drift more dangerously than the
rule it guards. Optimize stays outside the check for the same reason migration
and import do: it repairs existing geometry.
test_parity_with_the_frontend_checks feeds identical fixtures to the TS
functions and to this module and demands the same verdict, so the two
implementations cannot silently diverge.
Issue: #329
User-Visible: no
