按建议，继续完成后续工作

结论：已新增 OPFS host-side 路径模型，覆盖 INI、tool table、parameter、G-code、preview cache 与 session snapshot 存储目标，并让 file-service 和浏览器 smoke 复用该模型；聚合 smoke 验证通过。

wasm-port/runtime/opfs/file-service.js

@@ -1,17 +1,4 @@
-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;
-}
+import { splitOpfsPath } from "./path-model.js";
 
 export async function getOpfsRoot(storage = globalThis.navigator?.storage) {
   if (!storage?.getDirectory) {
@@ -21,7 +8,7 @@ export async function getOpfsRoot(storage = globalThis.navigator?.storage) {
 }
 
 export async function ensureParentDir(root, path) {
-  const parts = splitPath(path);
+  const parts = splitOpfsPath(path);
   let current = root;
   for (const part of parts.slice(0, -1)) {
     current = await current.getDirectoryHandle(part, { create: true });
@@ -32,7 +19,7 @@ export async function ensureParentDir(root, path) {
 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 filename = splitOpfsPath(path).at(-1);
   const fileHandle = await dir.getFileHandle(filename, { create: true });
   const writable = await fileHandle.createWritable();
   await writable.write(text);
@@ -41,7 +28,7 @@ export async function saveTextFile(path, text, storage) {
 
 export async function loadTextFile(path, storage) {
   const root = await getOpfsRoot(storage);
-  const parts = splitPath(path);
+  const parts = splitOpfsPath(path);
   let current = root;
   for (const part of parts.slice(0, -1)) {
     current = await current.getDirectoryHandle(part);

wasm-port/runtime/opfs/path-model.js

@@ -0,0 +1,101 @@
+const ROOT = "linuxcnc";
+
+function assertSegment(segment, label = "path segment") {
+  if (typeof segment !== "string" || segment.length === 0) {
+    throw new Error(`${label} must be a non-empty string.`);
+  }
+  if (
+    segment === "." ||
+    segment === ".." ||
+    segment.includes("/") ||
+    segment.includes("\\") ||
+    segment.includes("\0")
+  ) {
+    throw new Error(`Invalid ${label}: ${segment}`);
+  }
+  return segment;
+}
+
+export function splitOpfsPath(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 function normalizeOpfsPath(path) {
+  return splitOpfsPath(path).join("/");
+}
+
+export function opfsPath(...segments) {
+  return segments.map((segment) => assertSegment(segment)).join("/");
+}
+
+export function machineRoot(machineId) {
+  return opfsPath(ROOT, "machines", assertSegment(machineId, "machine id"));
+}
+
+export function machineIniPath(machineId, filename = "machine.ini") {
+  return opfsPath(
+    ROOT,
+    "machines",
+    assertSegment(machineId, "machine id"),
+    assertSegment(filename, "INI filename"),
+  );
+}
+
+export function toolTablePath(machineId, filename = "tool.tbl") {
+  return opfsPath(
+    ROOT,
+    "machines",
+    assertSegment(machineId, "machine id"),
+    assertSegment(filename, "tool table filename"),
+  );
+}
+
+export function parameterFilePath(machineId, filename = "linuxcnc.var") {
+  return opfsPath(
+    ROOT,
+    "machines",
+    assertSegment(machineId, "machine id"),
+    assertSegment(filename, "parameter filename"),
+  );
+}
+
+export function gcodeProgramPath(filename) {
+  return opfsPath(ROOT, "gcode", assertSegment(filename, "G-code filename"));
+}
+
+export function previewCachePath(cacheKey, filename = "preview.json") {
+  return opfsPath(
+    ROOT,
+    "preview-cache",
+    assertSegment(cacheKey, "preview cache key"),
+    assertSegment(filename, "preview cache filename"),
+  );
+}
+
+export function sessionSnapshotPath(sessionId, filename = "snapshot.json") {
+  return opfsPath(
+    ROOT,
+    "sessions",
+    assertSegment(sessionId, "session id"),
+    assertSegment(filename, "session snapshot filename"),
+  );
+}
+
+export function defaultMachinePaths(machineId) {
+  return {
+    ini: machineIniPath(machineId),
+    toolTable: toolTablePath(machineId),
+    parameters: parameterFilePath(machineId),
+  };
+}