CIRCLE/ARC no longer make a negative radius positive; POLYGON refuses a
non-integer sides count and a zero/negative radius or zero-length edge;
DONUT, RECTANG, PLINE, HATCH and TABLE refuse negative or zero sizes
instead of clamping them; LINE drops repeated points like the interactive
command; SPLINE needs two different fit points; DIMRADIUS/DIMDIAMETER/
DIMANGULAR refuse coincident points; DDPTYPE refuses an invalid PDMODE;
DIMSTYLE/DIMOVERRIDE list a non-positive DIMTXT/DIMTFAC or a negative
DIMASZ/DIMSCALE/DIMTSZ as ignored.
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
