按推荐建议，继续执行

结论：新增 compatibility-validation 与 drift-report，记录当前 native 验证链路、fixture 覆盖、无漂移规则和已知缺口，继续约束移植行为跟随 LinuxCNC 源程序。

wasm-port/docs/porting-steps-standalone.md

@@ -500,6 +500,11 @@ Current verified progress:
 - `docs/source-reuse-map.md` records the current vendored LinuxCNC source
   reuse matrix and dependency matrix, tying each extracted group to its
   standalone runtime boundary and validation path.
+- `docs/compatibility-validation.md` records the current validation chain,
+  source coverage requirements, native harnesses, fixture coverage, and
+  validation boundaries.
+- `docs/drift-report.md` records current no-drift enforcement, allowed
+  standalone runtime boundaries, known gaps, and the current drift conclusion.
 
 ## Phase 4: Port INI Parsing Without Editing Upstream