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/compatibility-validation.md

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+# Compatibility Validation
+
+## Purpose
+
+This document records how the standalone LinuxCNC WASM port currently proves
+that migrated behavior remains tied to LinuxCNC source code and fixture
+semantics.
+
+The primary validation command is:
+
+```bash
+wasm-port/tests/native/verify_native_probes.sh
+```
+
+## Validation Chain
+
+The native validation script runs these checks in order:
+
+1. `tools/verify_upstream_baseline.sh`
+   Confirms `../linuxcnc` is at the recorded upstream commit in
+   `tools/upstream-baseline.txt`.
+2. `tools/verify_vendor_sync.sh`
+   Confirms every manifest file is present in `vendor/linuxcnc/`, no extra
+   vendored file exists, and every vendored file is byte-identical to upstream.
+3. `tools/verify_no_standalone_cnc_semantics.sh`
+   Confirms standalone code has not reintroduced `Interp::convert_g()`.
+4. `tools/build_native_probes.sh`
+   Builds native source probes and standalone harnesses from vendored
+   LinuxCNC source plus narrow runtime wrappers.
+5. `tests/native/verify_native_probes.sh`
+   Checks probe exit codes, source-probe coverage, harness stdout, canonical
+   fixture events, and expected error behavior.
+
+## Source Coverage
+
+Every `.c` and `.cc` entry in `tools/source-manifest.txt` must have a
+corresponding `*_source_probe` entry in `build/native/source-probes.tsv`.
+The validation fails if:
+
+- a manifest source file lacks a source probe;
+- a source probe references a file not listed in the manifest;
+- a manifest file is duplicated;
+- vendored files drift byte-for-byte from upstream LinuxCNC.
+
+## Current Native Harnesses
+
+| Harness | Purpose |
+| --- | --- |
+| `linuxcnc_ini_probe` | Validates vendored LinuxCNC INI parsing can be used standalone. |
+| `linuxcnc_interp_state_probe` | Validates interpreter state constants and structs compile under the standalone boundary. |
+| `linuxcnc_namedparam_harness` | Validates LinuxCNC named parameter behavior, `_ini[...]`, and `_hal[...]` adapter resolution. |
+| `linuxcnc_interp_minimal_harness` | Runs G-code fixtures through vendored LinuxCNC parser/execution/conversion code and captures canonical events. |
+| `linuxcnc_parameter_file_harness` | Validates LinuxCNC parameter file restore/save behavior and required/read-only parameter handling. |
+| `linuxcnc_tp_api_probe` | Validates vendored LinuxCNC trajectory planner calls for linear, arc, and queued motion paths. |
+
+## Fixture Coverage
+
+Positive G-code fixtures currently cover:
+
+- linear traverse/feed
+- arc semantics
+- modal absolute/incremental motion
+- position parameters
+- canned cycles
+- coordinate offsets
+- feed and motion control modes
+- probing
+- threading and rigid tap
+- NURBS G5/G6
+- spindle orient
+- tool semantics
+- tool table setup
+- named and numbered parameters
+- O-word subroutines
+- program-end modal reset
+- canonical runtime edge calls
+
+Negative fixtures currently cover:
+
+- zero-feed `G1`
+- arc radius mismatch
+- zero-radius arc
+- read-only named parameter writes
+- read-only numbered parameter writes
+- missing tool
+- missing tool length offset
+
+## Validation Boundaries
+
+Current validation is native-only. WASM, browser, SDK, OPFS, and full
+machine-session validation remain future work.
+
+The current fixture expectations validate standalone behavior against the
+vendored LinuxCNC source path. They do not yet run a side-by-side native
+LinuxCNC executable comparison for each fixture.