The PROFILE record, centred assembly, and three complete arrangements:
ring, spokes, fins. Each written for N members, exercised at N=3 and N=4.
Failure travels as an empty profile carrying one failing check, as in the
reference, so profile rejections and universal-check rejections stay in
one order-sensitive list and the first failure is what surfaces.
The section is cleaned before it is measured, not after. A Three-Fin
section carries 17 collinear vertices from exact butt joints; they are
harmless in 2D and leave zero-area triangles the tessellator cannot
resolve, so measuring first would report on geometry that is not what
gets extruded.
Centred now carries the shifted members. Measuring a shifted shell
against unshifted members reports every cavity as escaping the envelope,
a leak of the whole cavity area from geometry that is fine. That trap
caught me while smoke testing, so the opportunity is removed rather than
documented.
Verified against the oracle where the fillet does not affect the result:
SPOKE_RADIUS_MM 9.1713, FIN_CORE_SIDE_MM 13.4028, FIN_SETBACK_MM
3.77783, FIN_JUNCTION_WEB_MM 2.29919, RING_CORNER_R_MAX_MM 2.87663, the
ring edge vector, and both envelope dimensions all match to the recorded
digit. The solvers are right.
OPEN: with a junction fillet of 1.5 the Y section area is 135.572973
against a recorded 135.574, off by 0.001027 and just past the area
tolerance, while every other quantity for that case matches exactly.
Either the generator fillet default is not 1.5, or there is a difference
of about seven parts per million concentrated in the fillet. The
generator settles it.
35 tests. Nine mutations, two of which found real gaps: nothing asserted
that cleaning removed anything, and the spoke zero-fillet check was
untested.
Oracle acceptance still skips; 236 unchanged.
