按建议，继续完成后续工作

结论：已将 INI 面板的 OPFS 文本文件读写抽为 host-side file-service，并新增 Node mock 验证，确认 OPFS 边界不进入 WASM core 且可覆盖保存、读取、缺失路径和非法路径行为。

wasm-port/runtime/ui/ini-panel/app.js

@@ -1,4 +1,9 @@
 import createLinuxCncIniModule from "./linuxcnc_ini.js";
+import {
+  getOpfsRoot,
+  loadTextFile,
+  saveTextFile,
+} from "../../opfs/file-service.js";
 
 const SAMPLE_PATH =
   "../../../linuxcnc/configs/sim/axis/vismach/5axis/table-dual-rotary/xyzab-tdr.ini";
@@ -70,44 +75,6 @@ function iniQuery(mod, wasmPath, section, tag) {
   }
 }
 
-async function getOpfsRoot() {
-  if (!navigator.storage?.getDirectory) {
-    throw new Error("OPFS is not available in this browser.");
-  }
-  return navigator.storage.getDirectory();
-}
-
-async function ensureParentDir(root, path) {
-  const parts = path.split("/");
-  let current = root;
-  for (const part of parts.slice(0, -1)) {
-    current = await current.getDirectoryHandle(part, { create: true });
-  }
-  return current;
-}
-
-async function saveToOpfs(path, text) {
-  const root = await getOpfsRoot();
-  const dir = await ensureParentDir(root, path);
-  const filename = path.split("/").at(-1);
-  const fileHandle = await dir.getFileHandle(filename, { create: true });
-  const writable = await fileHandle.createWritable();
-  await writable.write(text);
-  await writable.close();
-}
-
-async function loadFromOpfs(path) {
-  const root = await getOpfsRoot();
-  const parts = path.split("/");
-  let current = root;
-  for (const part of parts.slice(0, -1)) {
-    current = await current.getDirectoryHandle(part);
-  }
-  const fileHandle = await current.getFileHandle(parts.at(-1));
-  const file = await fileHandle.getFile();
-  return file.text();
-}
-
 function syncEditorToWasmFs() {
   const mod = requireModule();
   try {
@@ -157,7 +124,7 @@ document.getElementById("load-sample").addEventListener("click", async () => {
 
 document.getElementById("save-opfs").addEventListener("click", async () => {
   try {
-    await saveToOpfs(OPFS_FILE, editor.value);
+    await saveTextFile(OPFS_FILE, editor.value);
     setLog(`Saved current INI text to OPFS at ${OPFS_FILE}`);
   } catch (error) {
     setLog(`OPFS save failed: ${error.message}`, true);
@@ -166,7 +133,7 @@ document.getElementById("save-opfs").addEventListener("click", async () => {
 
 document.getElementById("load-opfs").addEventListener("click", async () => {
   try {
-    editor.value = await loadFromOpfs(OPFS_FILE);
+    editor.value = await loadTextFile(OPFS_FILE);
     setLog(`Loaded INI text from OPFS path ${OPFS_FILE}`);
   } catch (error) {
     setLog(`OPFS load failed: ${error.message}`, true);