按建议，继续完成后续工作

结论：已新增 OPFS machine file store，支持 INI、tool table、parameter file 和 G-code 的纯文本保存/读取，并在 Node mock 与 Chromium smoke 中验证往返，不引入 CNC 文件格式语义。

wasm-port/runtime/opfs/machine-file-store.js

@@ -0,0 +1,54 @@
+import { loadTextFile, saveTextFile } from "./file-service.js";
+import {
+  gcodeProgramPath,
+  machineIniPath,
+  parameterFilePath,
+  toolTablePath,
+} from "./path-model.js";
+
+const MACHINE_FILE_PATHS = {
+  ini: machineIniPath,
+  toolTable: toolTablePath,
+  parameters: parameterFilePath,
+};
+
+export function machineFilePaths(machineId) {
+  return {
+    ini: machineIniPath(machineId),
+    toolTable: toolTablePath(machineId),
+    parameters: parameterFilePath(machineId),
+  };
+}
+
+export async function saveMachineTextFiles(machineId, files, options = {}) {
+  if (files === null || typeof files !== "object" || Array.isArray(files)) {
+    throw new Error("machine files must be a plain object.");
+  }
+
+  const paths = machineFilePaths(machineId);
+  for (const [name, pathFor] of Object.entries(MACHINE_FILE_PATHS)) {
+    if (Object.hasOwn(files, name)) {
+      await saveTextFile(pathFor(machineId), String(files[name]), options.storage);
+    }
+  }
+  return paths;
+}
+
+export async function loadMachineTextFiles(machineId, options = {}) {
+  const paths = machineFilePaths(machineId);
+  return {
+    ini: await loadTextFile(paths.ini, options.storage),
+    toolTable: await loadTextFile(paths.toolTable, options.storage),
+    parameters: await loadTextFile(paths.parameters, options.storage),
+  };
+}
+
+export async function saveGcodeProgram(filename, text, options = {}) {
+  const path = gcodeProgramPath(filename);
+  await saveTextFile(path, text, options.storage);
+  return path;
+}
+
+export async function loadGcodeProgram(filename, options = {}) {
+  return loadTextFile(gcodeProgramPath(filename), options.storage);
+}