参考所有分组，完成尽量多的内容：结论为 build-wasm 显式关闭 smoke 后端

docs/linuxcnc-source-policy.md

@@ -290,6 +290,9 @@ Build and source-link guardrails:
   `rs274ngc_pre` link checks.
 - `build-wasm.sh` must check `cmake`, `emcmake`, `emcc`, and `node` before the
   Emscripten configure step.
+- `build-wasm.sh` must explicitly configure `CNC_SIM_ENABLE_SMOKE_BACKEND=OFF`
+  while enabling `CNC_SIM_ENABLE_LINUXCNC_WASM_SAFE_PROBE=ON`, so stale CMake
+  cache values cannot route browser artifacts through the legacy smoke backend.
 - `build-wasm.sh` must reuse a persistent `build/wasm` configure signature
   keyed by manifest, `core/CMakeLists.txt`, an explicit
   `CONFIGURE_RULE_VERSION`, LinuxCNC root, and compiler launcher. The signature