按推荐建议，继续执行

结论：记录 LinuxCNC 上游 commit 与本地构建/fixture 基线，新增 upstream baseline 验证并接入 native 验证，确保 vendored 源码同步绑定到明确的 LinuxCNC 源程序版本。

wasm-port/tools/upstream-baseline.txt

@@ -0,0 +1 @@
+60597ee0718873d2449058c824262a275e5e4bad

wasm-port/tools/verify_upstream_baseline.sh

@@ -0,0 +1,34 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+ROOT_DIR="$(cd "$(dirname "$0")/.." && pwd)"
+UPSTREAM_DIR="$ROOT_DIR/../linuxcnc"
+BASELINE_FILE="$ROOT_DIR/tools/upstream-baseline.txt"
+
+if [[ ! -d "$UPSTREAM_DIR/.git" ]]; then
+  echo "missing upstream git repository: $UPSTREAM_DIR" >&2
+  exit 1
+fi
+
+if [[ ! -f "$BASELINE_FILE" ]]; then
+  echo "missing upstream baseline file: $BASELINE_FILE" >&2
+  exit 1
+fi
+
+expected="$(sed -n '1p' "$BASELINE_FILE" | tr -d '[:space:]')"
+actual="$(git -C "$UPSTREAM_DIR" rev-parse HEAD)"
+
+if [[ -z "$expected" ]]; then
+  echo "empty upstream baseline file: $BASELINE_FILE" >&2
+  exit 1
+fi
+
+if [[ "$actual" != "$expected" ]]; then
+  echo "upstream baseline mismatch:" >&2
+  echo "  expected: $expected" >&2
+  echo "  actual:   $actual" >&2
+  echo "Update tools/upstream-baseline.txt and docs/scope-and-baseline.md only after an intentional upstream sync." >&2
+  exit 1
+fi
+
+echo "upstream baseline validation complete"