按建议，继续工作

结论：已新增 cutter compensation 平面切换拒绝 fixture，固定 vendored LinuxCNC convert_cutter_compensation_on() 与 convert_set_plane() 的错误路径；native probe 全量验证通过。

wasm-port/docs/scope-and-baseline.md

@@ -56,6 +56,7 @@ Negative fixture coverage includes:
 - zero-feed `G1`
 - arc radius mismatch
 - zero-radius arc
+- cutter compensation plane-change rejection
 - read-only named parameter writes
 - read-only numbered parameter writes
 - missing tool