Kernel rig: every fillet and chamfer case rounds its tangent chain

The owner's ruling of 2026-11-01: the rig and the ladder round with tangent_chain true, how a
user's default pick behaves. The 38 fillets-area recipes and the ladder's 07-fillets/016 and 018
that passed false now pass true. The shell recipes keep theirs: a shell's tangent_chain is its
open-face chain, a different feature.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DtL5M41G8Nua7HvuFPZkmJ

tests/kernel-cases/fillets/1080-fillet-notched-block-top-outline-r7/recipe.json

@@ -48,7 +48,7 @@
      ]
     ],
     "radius": 7,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/fillets/1080-fillet-notched-block-top-outline-r8/recipe.json

@@ -48,7 +48,7 @@
      ]
     ],
     "radius": 8,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/fillets/1113-chamfer-arc-top-edge-full-wall-height/recipe.json

@@ -72,7 +72,7 @@
      ]
     ],
     "distance": 10,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/fillets/1207-fillet-box-end-edge-into-unblended-round/recipe.json

@@ -33,7 +33,7 @@
      ]
     ],
     "radius": 1,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/fillets/318-fillet-plate-top-outline-as-tall-as-wall/recipe.json

@@ -34,7 +34,7 @@
      ]
     ],
     "radius": 5,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/fillets/851-chamfer-arc-and-top-front-2/recipe.json

@@ -77,7 +77,7 @@
      ]
     ],
     "distance": 2,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/fillets/851-chamfer-arc-top-edge-9-5/recipe.json

@@ -72,7 +72,7 @@
      ]
     ],
     "distance": 9.5,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/fillets/851-chamfer-knife-edge-tip-2-box-less-cylinder/recipe.json

@@ -37,7 +37,7 @@
      ]
     ],
     "distance": 2,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/fillets/851-chamfer-knife-edge-tip-2-sketched/recipe.json

@@ -113,7 +113,7 @@
      ]
     ],
     "distance": 2,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/fillets/851-chamfer-knife-edge-tip-5/recipe.json

@@ -72,7 +72,7 @@
      ]
     ],
     "distance": 5,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/fillets/851-fillet-arc-and-upright/recipe.json

@@ -77,7 +77,7 @@
      ]
     ],
     "radius": 2,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/fillets/851-fillet-arc-then-top-front/recipe.json

@@ -72,7 +72,7 @@
      ]
     ],
     "radius": 2,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   },
   {
@@ -86,7 +86,7 @@
      ]
     ],
     "radius": 2,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/fillets/851-fillet-arc-top-edge-9-5/recipe.json

@@ -72,7 +72,7 @@
      ]
     ],
     "radius": 9.5,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/fillets/851-fillet-arc-top-edge-full-wall-height/recipe.json

@@ -72,7 +72,7 @@
      ]
     ],
     "radius": 10,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/fillets/851-fillet-knife-edge-tip-r2/recipe.json

@@ -72,7 +72,7 @@
      ]
     ],
     "radius": 2,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/fillets/851-fillet-top-front-and-arc/recipe.json

@@ -77,7 +77,7 @@
      ]
     ],
     "radius": 2,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/fillets/851-fillet-top-front-and-front-left-upright/recipe.json

@@ -77,7 +77,7 @@
      ]
     ],
     "radius": 2,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/fillets/851-fillet-top-front-and-upright/recipe.json

@@ -77,7 +77,7 @@
      ]
     ],
     "radius": 2,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/fillets/851-fillet-top-front-then-front-left-upright/recipe.json

@@ -72,7 +72,7 @@
      ]
     ],
     "radius": 2,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   },
   {
@@ -86,7 +86,7 @@
      ]
     ],
     "radius": 2,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/fillets/851-fillet-top-front-then-upright/recipe.json

@@ -72,7 +72,7 @@
      ]
     ],
     "radius": 2,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   },
   {
@@ -86,7 +86,7 @@
      ]
     ],
     "radius": 2,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

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

@@ -31,7 +31,7 @@
     ],
     "radius": 5,
     "corner": "g2",
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/fillets/cov-fillet-pocket-floor-round-corners-r3-chain-r1/recipe.json

@@ -86,7 +86,7 @@
      ]
     ],
     "radius": 3.0,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   },
   {

tests/kernel-cases/fillets/cov-fillet-turn-mitre-boss-base-r1/recipe.json

@@ -52,7 +52,7 @@
      ]
     ],
     "radius": 1.0,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/fillets/cov-fillet-turn-mitre-pocket-floor-corners-r1/recipe.json

@@ -86,7 +86,7 @@
      ]
     ],
     "radius": 1.0,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/fillets/cov-fillet-turn-swept-boss-base-r1/recipe.json

@@ -52,7 +52,7 @@
      ]
     ],
     "radius": 1.0,
-    "tangent_chain": false,
+    "tangent_chain": true,
     "turn": "swept"
    }
   }

tests/kernel-cases/fillets/cov-fillet-turn-swept-pocket-sharp-corner-refused-r1/recipe.json

@@ -86,7 +86,7 @@
      ]
     ],
     "radius": 1.0,
-    "tangent_chain": false,
+    "tangent_chain": true,
     "turn": "swept"
    }
   }

tests/kernel-cases/fillets/every-block-cylinder-crease-block-top-edge-r2-no-tangent-chain/recipe.json

@@ -41,7 +41,7 @@
      ]
     ],
     "radius": 2,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/fillets/every-block-cylinder-tangent-block-top-edge-r2-no-tangent-chain/recipe.json

@@ -41,7 +41,7 @@
      ]
     ],
     "radius": 2,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/fillets/every-block-cylinder-tangent-concave-arc-r2-no-tangent-chain/recipe.json

@@ -41,7 +41,7 @@
      ]
     ],
     "radius": 2,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/fillets/every-box-corner-three-edges-r3-curvature-setback-3-5/recipe.json

@@ -31,7 +31,7 @@
     ],
     "radius": 3,
     "corner": "g2",
-    "tangent_chain": false,
+    "tangent_chain": true,
     "setbacks": [
      {
       "vertex": [

tests/kernel-cases/fillets/every-box-corner-three-edges-r3-curvature-setback-3-refused/recipe.json

@@ -31,7 +31,7 @@
     ],
     "radius": 3,
     "corner": "g2",
-    "tangent_chain": false,
+    "tangent_chain": true,
     "setbacks": [
      {
       "vertex": [

tests/kernel-cases/fillets/every-fillet-after-fillet-curvature-front-then-side-r3/recipe.json

@@ -35,7 +35,7 @@
     ],
     "radius": 3,
     "type": "curvature",
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/fillets/report-fillet-curvature-three-edges-at-bar-corner-solver-residues-outside-setback/recipe.json

@@ -174,7 +174,7 @@
     ],
     "radius": 2,
     "type": "curvature",
-    "tangent_chain": false
+    "tangent_chain": true
    }
   },
   {

tests/kernel-cases/fillets/report-fillet-curvature-three-edges-at-bar-corner-solver-residues/recipe.json

@@ -174,7 +174,7 @@
     ],
     "radius": 2,
     "type": "curvature",
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/fillets/report-fillet-curvature-three-edges-at-bar-corner/recipe.json

@@ -174,7 +174,7 @@
     ],
     "radius": 2,
     "type": "curvature",
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/fillets/report-fillet-g2-corner-of-bar-running-into-cylinder-outside-setback/recipe.json

@@ -184,7 +184,7 @@
       "distance": 3
      }
     ],
-    "tangent_chain": false
+    "tangent_chain": true
    }
   },
   {

tests/kernel-cases/fillets/report-fillet-g2-corner-of-bar-running-into-cylinder/recipe.json

@@ -184,7 +184,7 @@
       "distance": 3
      }
     ],
-    "tangent_chain": false
+    "tangent_chain": true
    }
   }
  ]

tests/kernel-cases/ladder/07-fillets/016-corner-three-sequential-r5-r3-r7/recipe.json

@@ -25,7 +25,7 @@
      ]
     ],
     "radius": 3,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   },
   {

tests/kernel-cases/ladder/07-fillets/018-corner-three-sequential-r5-r3-r2/recipe.json

@@ -25,7 +25,7 @@
      ]
     ],
     "radius": 3,
-    "tangent_chain": false
+    "tangent_chain": true
    }
   },
   {