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/drift-report.md

@@ -0,0 +1,60 @@
+# Drift Report
+
+## Current Status
+
+As of the current upstream baseline, no byte-level drift is allowed between
+files listed in `tools/source-manifest.txt` and the matching files under
+`../linuxcnc/`.
+
+The enforced upstream baseline is:
+
+```text
+60597ee0718873d2449058c824262a275e5e4bad
+```
+
+`tools/verify_vendor_sync.sh` enforces this by comparing every manifest file
+against upstream during native validation.
+
+## Allowed Standalone Boundaries
+
+The following differences are intentional runtime boundaries, not LinuxCNC
+semantic rewrites:
+
+| Boundary | Standalone treatment |
+| --- | --- |
+| RTAPI | Minimal compatibility shim in `runtime/core/shims/rtapi.h`. |
+| HAL lookup | Standalone HAL adapter for `_hal[...]` named parameter reads. |
+| INI lookup | Standalone INI adapter around vendored LinuxCNC INI parser behavior. |
+| Canonical output | Canonical calls are captured as test events instead of driving hardware. |
+| Python/remap | Python/remap hooks are stubbed at the runtime edge. |
+| Dynamic interpreter path | `interp_base.cc` probe uses standalone `EMC2_HOME` compile-time path boundary. |
+| Realtime scheduler | TP probes seed deterministic status/config data instead of running LinuxCNC realtime process topology. |
+| Browser storage | OPFS remains outside the native core and is not yet connected. |
+
+## Enforced Non-Drift Rules
+
+- Do not edit `../linuxcnc/`.
+- Do not patch vendored files without adding a patch under `patches/` and
+  documenting the reason.
+- Do not add standalone `Interp::convert_g()`.
+- Do not add `.c` or `.cc` manifest files without a source compile probe.
+- Do not sync from a different upstream commit without updating
+  `tools/upstream-baseline.txt` and `docs/scope-and-baseline.md`.
+
+## Known Gaps
+
+- No browser/WASM parity tests yet.
+- No JS SDK validation yet.
+- No OPFS persistence validation yet.
+- Full kinematics implementation files are not yet extracted.
+- Full 3-axis, non-trivial kinematics, and 5-axis machine baselines are not
+  established.
+- Fixture expectations are currently checked against the standalone vendored
+  source path, not by running a native LinuxCNC binary for every fixture.
+
+## Current Drift Conclusion
+
+Within the native extracted-core scope, the port currently has no permitted
+byte-level drift from vendored LinuxCNC source files. All current behavior
+coverage is guarded by upstream baseline validation, vendor sync validation,
+source compile probes, native harnesses, and fixture checks.