Shell and Offset Face on drill tips and tori: samples skip points where the normal is undefined (a cone's apex), the apex moves with its cone, tori offset their tube (the tube circle scaled and revolved again); a box with a drilled hole now shells to its analytic volume

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL

crates/engine/src/cmd/mod.rs

@@ -20,6 +20,8 @@ pub(crate) mod motion;
 mod parts;
 mod section;
 pub(crate) use measure_sel::measure_items;
+#[cfg(test)]
+mod kernel_heal_tests;
 mod parameters;
 mod plastic;
 mod sheet;