Known failing: the law corners' kernel and crate tests and rig 1207 pass on SMLib 48ea616

SMLib builds a variable round's law corners as its balls' union (the corner
ball's zone at a dip, the sides' crossing at a peak): the kernel's corner
through a middle point (39.5410) and the crate's 4 -> 2 -> 4 law (39.5421) pass.
Rig 1207 (the bar's top edge rounded after the boss's arc, r0.5) builds and
grades on the same SMLib; it failed on c820346.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/KNOWN_FAILING_TESTS

@@ -15,8 +15,6 @@ solidcraft-kernel::blend::corner_tests::a_round_ending_in_an_earlier_round_match
 solidcraft-kernel::blend::corner_tests::corner_blends_hold_at_any_scale at 0.01x the arc case's rounds remove 72.783 (scaled back) against 72.713 at 1x (9.6e-4 off, 1e-4 allowed)
 solidcraft-kernel::blend_corner::tests::issue2422_vertical_after_separate_bottom_rounds SMLib's check refuses the fillet: edge and vertex tolerance 0.97 against the body's 0.01 (#2422)
 solidcraft-kernel::blend_corner::tests::three_rounds_at_a_corner the corner's variable-radius transition between rounds of different radii (its elliptic law, a rail edge the corner interpolates) meets its neighbours at 0.144 degrees once its sections are the balls' touch circles (0 with the great circles); the corner step replaces that transition
-solidcraft-kernel::blend_variable::tests::variable_radius_with_a_corner_through_a_middle_point the two halves' rounds are joined from their own end circles at the law's corner, not where they cross: 39.8302 removed against 39.5410
 solidcraft-kernel::corner_g2::tests::a_long_setback_keeps_the_g2_patch_inside_the_box at set backs 11 to 15 the G2 corner patch bulges 2.6e-6 to 1.33e-3 past the box (the explicit corner is in progress)
 solidcraft-kernel::corner_g2::tests::the_box_corner_g2_patch_is_a_closed_solid_curvature_continuous_to_its_neighbours the fitted G2 corner patch bulges 1.7e-5 past the box, which SMLib's exact tight box now sees (the explicit G2 corner builds it inside)
 solidcraft-kernel::tests::fillet_tabbed_plate_outer_loop_and_partial_selection_after_hole the arc and tab rounds together remove 9.20067 against 9.20420 (3.8e-4 off, 1e-5 allowed)
-solidcraft-smlib::ops::tests::a_variable_round_with_a_corner_in_its_law_is_its_balls_union the two halves' rounds are joined from their own end circles at the law's corner; the ball's sphere between its two touch circles is not built: 39.6456 removed against 39.5421

tests/kernel-cases/fillets/KNOWN_FAILING

@@ -5,7 +5,6 @@
 1080-fillet-equal-slope-basin-1-mm-rim-loop-4 builds to the analytic volume (rel 5e-9), but the continuity check (g1 at every blend seam) takes in the mitre's creases, G0 by the mitre ruling: the case's continuity seams need the owner's word
 1080-fillet-sloped-basin-1-mm-rim-r4-2-edges builds to the analytic volume (rel 6e-9), but the continuity check (g1 at every blend seam) takes in the mitre's creases, G0 by the mitre ruling: the case's continuity seams need the owner's word
 1080-fillet-sloped-basin-1-mm-rim-r4-4-edges builds to the analytic volume (rel 3e-9), but the continuity check (g1 at every blend seam) takes in the mitre's creases, G0 by the mitre ruling: the case's continuity seams need the owner's word
-1207-fillet-bar-top-edge-after-boss-arc-round-r0-5 SMLib's check refuses the round: internal coincident control points in its end rib on the boss, which starts where the round and the boss are tangent (the boss's intersection marched there in spans down to 6e-8 mm)
 2893-chamfer-distance-and-angle-past-the-wall-refused refused for another reason: SMLib SM_ERR_INVALID_INPUT, not a check saying the angle runs past the wall
 2893-chamfer-two-distances-elliptical-rim SMLib status 1001: the two arcs of the rim take their chamfer offsets each at its own midpoint, where the faces' angle differs (78.5 and 101.5 deg), and their chamfers do not meet at the tangent corners (held for the owner's ruling on unequal chamfers of a varying angle)
 4782-fillet-bar-edge-wider-than-both-faces SMLib status 1001: a convex round past both its faces is not yet built by subtraction