Kernel rig: the two G2 corner cases are graded clear of the vertices, as the ladder grades them

Where a round meets a plane it is only tangent to it: its curvature jumps by 1/r there, so no
corner patch can be G2 to both at that point. The cases graded the whole seam and could not pass.
They now bound the curvature jump at stations clear of each seam's turn, within reach of the
corner, scaled by r (ladder 07/019's bound at r5): r1 within 2.2 mm, 0.24 mm clear, 0.005 per mm;
r5 within 11 mm, 1.2 mm clear, 0.001 per mm. Develop's corner gives 0.00135 and 0.00027 per mm
(the jump at the vertex is 1.017 and 0.2035, the round's own 1/r), so both leave KNOWN_FAILING.

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

tests/kernel-cases/fillets/9-fillet-corner-r1-curvature-default-setback/expected.json

@@ -2,9 +2,9 @@
  "sources": [
   "tangency-labs/solidcraft#9"
  ],
- "what": "three r1 rounds at a box corner with the curvature (g2) corner at its default setback 1.5 r: the corner patch must meet the rounds and faces G2 (today it is G1 at the corner point)",
+ "what": "three r1 rounds at a box corner with the curvature (g2) corner at its default setback 1.5 r: the corner patch meets the rounds and faces G2 clear of the vertices where the seams turn",
  "source": "invariants",
- "method": "as ladder 07-fillets/015 at r1: the corner set back 1.5 and filled with one patch; no closed-form volume: one valid body, 6 faces + 3 rounds + the patch, within the box",
+ "method": "as ladder 07-fillets/015 at r1: the corner set back 1.5 and filled with one patch; no closed-form volume: one valid body, 6 faces + 3 rounds + the patch, within the box Graded as ladder 07/019, scaled by r: at a hole corner the round is only tangent (G1) to the plane, its curvature jumping by 1/r, so no patch is G2 to both there; the curvature jump is bounded at stations at least 0.24 mm (0.24 r) from each turn, within 2.2 mm of the corner, at most 0.005 per mm (0.5% of 1/r).",
  "body_count": 1,
  "faces": 10,
  "bbox": {
@@ -20,7 +20,13 @@
   ]
  },
  "continuity": {
-  "order": "g2",
-  "edges": "corner"
+  "near": [
+   60,
+   40,
+   20
+  ],
+  "within_mm": 2.2,
+  "clear_mm": 0.24,
+  "curvature_jump_per_mm": 0.005
  }
-}
+}

tests/kernel-cases/fillets/9-fillet-corner-r5-curvature-default-setback/expected.json

@@ -2,9 +2,9 @@
  "sources": [
   "tangency-labs/solidcraft#9"
  ],
- "what": "three r5 rounds at a box corner with the curvature (g2) corner at its default setback 1.5 r: the corner patch must meet the rounds and faces G2 (today it is G1 at the corner point)",
+ "what": "three r5 rounds at a box corner with the curvature (g2) corner at its default setback 1.5 r: the corner patch meets the rounds and faces G2 clear of the vertices where the seams turn",
  "source": "invariants",
- "method": "as ladder 07-fillets/015: box 60x40x20, the three edges at the corner (60, 40, 20) rounded r5 with corner g2, the corner set back 7.5 and filled with one patch built G2 to the three rounds and the three faces; no closed-form volume: one valid body, 6 faces + 3 rounds + the patch, within the box; every seam of the patch G2, measured as Continuity Analysis measures it",
+ "method": "as ladder 07-fillets/015: box 60x40x20, the three edges at the corner (60, 40, 20) rounded r5 with corner g2, the corner set back 7.5 and filled with one patch built G2 to the three rounds and the three faces; no closed-form volume: one valid body, 6 faces + 3 rounds + the patch, within the box; every seam of the patch G2, measured as Continuity Analysis measures it Graded as ladder 07/019, scaled by r: at a hole corner the round is only tangent (G1) to the plane, its curvature jumping by 1/r, so no patch is G2 to both there; the curvature jump is bounded at stations at least 1.2 mm (0.24 r) from each turn, within 11 mm of the corner, at most 0.001 per mm (0.5% of 1/r).",
  "body_count": 1,
  "faces": 10,
  "bbox": {
@@ -20,7 +20,13 @@
   ]
  },
  "continuity": {
-  "order": "g2",
-  "edges": "corner"
+  "near": [
+   60,
+   40,
+   20
+  ],
+  "within_mm": 11,
+  "clear_mm": 1.2,
+  "curvature_jump_per_mm": 0.001
  }
-}
+}

tests/kernel-cases/fillets/KNOWN_FAILING

@@ -8,5 +8,3 @@
 5158-fillet-round-just-past-a-10mm-face SMLib status 1001: a convex round 0.01 past its face is not yet built by subtraction (10.0001-10.04 open)
 9-fillet-corner-curvature-with-reduce-fit not supported yet: solid.fillet builds corner g2 with the exact fit only
 9-fillet-corner-curvature-with-taper-fit not supported yet: solid.fillet builds corner g2 with the exact fit only
-9-fillet-corner-r1-curvature-default-setback continuity g1: the g2 corner patch seams G1 at the corner point, not G2
-9-fillet-corner-r5-curvature-default-setback continuity g1: the g2 corner patch seams G1 at the corner point, not G2