按推荐建议，继续执行

结论：继续按 LinuxCNC 源码直接复用路线推进，新增 SCARA 运动学源码的 vendored 同步、switchkins native 探针、source probe 覆盖和复用文档，并通过 native 验证。

wasm-port/runtime/core/linuxcnc_wrap/linuxcnc_scara_kinematics_probe.cpp

@@ -0,0 +1,101 @@
+#include <cmath>
+#include <iostream>
+
+#include "emc/kinematics/kinematics.h"
+#include "emc/motion/emcmotcfg.h"
+
+int rtapi_app_main(void);
+void rtapi_app_exit(void);
+
+namespace {
+
+int near(double actual, double expected)
+{
+    return std::fabs(actual - expected) < 1e-9;
+}
+
+int near_joints(const double *actual, const double *expected)
+{
+    for (int index = 0; index < 6; ++index) {
+        if (!near(actual[index], expected[index])) {
+            return 0;
+        }
+    }
+    return 1;
+}
+
+int near_identity_pose(const EmcPose &actual, const double *joints)
+{
+    return near(actual.tran.x, joints[0]) &&
+           near(actual.tran.y, joints[1]) &&
+           near(actual.tran.z, joints[2]) &&
+           near(actual.a, joints[3]) &&
+           near(actual.b, joints[4]) &&
+           near(actual.c, joints[5]);
+}
+
+void print_pose(const char *prefix, const EmcPose &pose)
+{
+    std::cout << prefix << "_xyz="
+              << pose.tran.x << ","
+              << pose.tran.y << ","
+              << pose.tran.z << "\n";
+    std::cout << prefix << "_abc="
+              << pose.a << ","
+              << pose.b << ","
+              << pose.c << "\n";
+}
+
+void print_joints(const char *prefix, const double *joints)
+{
+    std::cout << prefix << "_xyzabc="
+              << joints[0] << ","
+              << joints[1] << ","
+              << joints[2] << ","
+              << joints[3] << ","
+              << joints[4] << ","
+              << joints[5] << "\n";
+}
+
+}  // namespace
+
+int main()
+{
+    const int init_rc = rtapi_app_main();
+    std::cout << "scara_init=" << init_rc << "\n";
+    std::cout << "scara_type=" << kinematicsType() << "\n";
+    std::cout << "scara_switchable=" << kinematicsSwitchable() << "\n";
+
+    double joints[EMCMOT_MAX_JOINTS]{};
+    joints[0] = 20.0;
+    joints[1] = 110.0;
+    joints[2] = 30.0;
+    joints[3] = 15.0;
+    joints[4] = 4.0;
+    joints[5] = 5.0;
+
+    KINEMATICS_FORWARD_FLAGS fflags = 0;
+    KINEMATICS_INVERSE_FLAGS iflags = 0;
+    EmcPose forward_pose{};
+    const int forward_rc = kinematicsForward(joints, &forward_pose, &fflags, &iflags);
+    std::cout << "scara_forward=" << forward_rc << "\n";
+    std::cout << "scara_forward_iflags=" << iflags << "\n";
+    print_pose("scara_forward", forward_pose);
+
+    double inverse_joints[EMCMOT_MAX_JOINTS]{};
+    const int inverse_rc = kinematicsInverse(&forward_pose, inverse_joints, &iflags, &fflags);
+    std::cout << "scara_inverse=" << inverse_rc << "\n";
+    print_joints("scara_inverse", inverse_joints);
+    std::cout << "scara_roundtrip_joints=" << near_joints(inverse_joints, joints) << "\n";
+
+    const int switch_rc = kinematicsSwitch(1);
+    std::cout << "scara_switch_identity=" << switch_rc << "\n";
+    EmcPose identity_pose{};
+    const int identity_forward_rc = kinematicsForward(joints, &identity_pose, &fflags, &iflags);
+    std::cout << "scara_identity_forward=" << identity_forward_rc << "\n";
+    print_pose("scara_identity", identity_pose);
+    std::cout << "scara_identity_near=" << near_identity_pose(identity_pose, joints) << "\n";
+
+    rtapi_app_exit();
+    return 0;
+}