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/opfs/file-service.js

@@ -0,0 +1,52 @@
+function splitPath(path) {
+  if (typeof path !== "string" || path.length === 0) {
+    throw new Error("OPFS path must be a non-empty relative path.");
+  }
+  if (path.startsWith("/") || path.includes("//")) {
+    throw new Error(`Invalid OPFS path: ${path}`);
+  }
+
+  const parts = path.split("/");
+  if (parts.some((part) => part === "." || part === ".." || part === "")) {
+    throw new Error(`Invalid OPFS path: ${path}`);
+  }
+  return parts;
+}
+
+export async function getOpfsRoot(storage = globalThis.navigator?.storage) {
+  if (!storage?.getDirectory) {
+    throw new Error("OPFS is not available in this browser.");
+  }
+  return storage.getDirectory();
+}
+
+export async function ensureParentDir(root, path) {
+  const parts = splitPath(path);
+  let current = root;
+  for (const part of parts.slice(0, -1)) {
+    current = await current.getDirectoryHandle(part, { create: true });
+  }
+  return current;
+}
+
+export async function saveTextFile(path, text, storage) {
+  const root = await getOpfsRoot(storage);
+  const dir = await ensureParentDir(root, path);
+  const filename = splitPath(path).at(-1);
+  const fileHandle = await dir.getFileHandle(filename, { create: true });
+  const writable = await fileHandle.createWritable();
+  await writable.write(text);
+  await writable.close();
+}
+
+export async function loadTextFile(path, storage) {
+  const root = await getOpfsRoot(storage);
+  const parts = splitPath(path);
+  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();
+}