参考所有分组，完成尽量多的内容。禁止顺手扩功能 smoke

结论：按 align-linuxcnc 约束收窄 OPFS removeFile 和 LinuxCNC 参数 .new/.bak 清理为文件专用语义，避免把同名目录递归删除。依据 ../linuxcnc/src/emc/rs274ngc/rs274ngc_pre.cc save_parameters() 的 fopen(filename.new)、unlink(filename.bak)、link、rename 行为。

验证：./test-native.sh 通过；./test-linuxcnc-source-link.sh 通过。

test-native.sh

@@ -366,7 +366,10 @@ if grep -R -n -E 'localStorage|sessionStorage|indexedDB|showOpenFilePicker|showS
 fi
 grep -F 'LinuxCNC source basis: rs274ngc_pre.cc restore_parameters() reads the' web/src/wasm-core.js >/dev/null
 grep -F 'before replacing the main file and managing filename + ".bak".' web/src/wasm-core.js >/dev/null
-grep -F 'await removeOpfsEntry(workspacePath, `${path}.new`, false);' web/src/wasm-core.js >/dev/null
+grep -F 'async function removeOpfsFileEntry(workspacePath, relativePath)' web/src/wasm-core.js >/dev/null
+grep -F 'await removeOpfsFileEntry(workspacePath, `${path}.new`);' web/src/wasm-core.js >/dev/null
+grep -F 'removeWasmFilePath(module, `${LINUXCNC_DEFAULT_PARAMETER_FILE}.new`);' web/src/wasm-core.js >/dev/null
+grep -F 'OPFS removeFile removed a directory instead of preserving file-only semantics' web/test-browser-wasm-smoke-opfs-directory-sections.js >/dev/null
 grep -F 'OPFS workspace is required for browser program parsing' web/src/app.js >/dev/null
 grep -F 'const events = await simulator.parseFileWithParameterFile(programPath, parameterPath, "linuxcnc", parseOptions);' web/src/app.js >/dev/null
 grep -F 'default browser simulator did not create an OPFS workspace' web/test-browser-wasm-smoke-opfs-policy-sections.js >/dev/null

web/src/wasm-core.js

@@ -318,6 +318,21 @@ function removeWasmPath(module, path, recursive) {
   }
 }
 
+function removeWasmFilePath(module, path) {
+  let mode;
+  try {
+    mode = module.FS.stat(path).mode;
+  } catch (error) {
+    if (error?.errno !== 44) {
+      throw error;
+    }
+    return;
+  }
+  if (module.FS.isFile(mode)) {
+    module.FS.unlink(path);
+  }
+}
+
 function wasmPathExists(module, path) {
   try {
     module.FS.stat(path);
@@ -505,9 +520,12 @@ function installOpfsWorkspace(module, options) {
         throw new Error("LinuxCNC parameter file was not produced by the interpreter");
       }
       await writeOpfsFile(workspacePath, path, data);
-      await removeOpfsEntry(workspacePath, `${path}.new`, false);
+      // LinuxCNC source basis: rs274ngc_pre.cc save_parameters()
-      removeWasmPath(module, `${LINUXCNC_DEFAULT_PARAMETER_FILE}.new`, false);
+      // creates filename + ".new" with fopen() and later renames that
-      removeWasmPath(module, `/${LINUXCNC_DEFAULT_PARAMETER_FILE}.new`, false);
+      // file; OPFS cleanup must not remove a directory at that path.
+      await removeOpfsFileEntry(workspacePath, `${path}.new`);
+      removeWasmFilePath(module, `${LINUXCNC_DEFAULT_PARAMETER_FILE}.new`);
+      removeWasmFilePath(module, `/${LINUXCNC_DEFAULT_PARAMETER_FILE}.new`);
       const backupPath = `${LINUXCNC_DEFAULT_PARAMETER_FILE}.bak`;
       const backupData = readFirstExistingWasmFile(module, [backupPath, `/${backupPath}`]);
       if (backupData !== null) {
@@ -518,8 +536,11 @@ function installOpfsWorkspace(module, options) {
       return data;
     },
     async removeFile(path) {
-      await removeOpfsEntry(workspacePath, path, false);
+      // LinuxCNC source basis: rs274ngc_pre.cc save_parameters() uses
-      removeWasmPath(module, this.resolvePath(path), false);
+      // unlink() for backup files, so the browser bridge keeps file-only
+      // removal separate from recursive directory cleanup.
+      await removeOpfsFileEntry(workspacePath, path);
+      removeWasmFilePath(module, this.resolvePath(path));
     },
     async removeDirectory(path) {
       await removeOpfsEntry(workspacePath, path, true);

web/test-browser-wasm-smoke-opfs-directory-sections.js

@@ -171,4 +171,20 @@ export async function runBrowserOpfsDirectorySections(context, simulator) {
       "OPFS removeDirectory did not remove the WASM mirror",
     );
   });
+
+  await runSection("opfs file removal preserves directories", async () => {
+    await simulator.fs.opfs.writeFile("parameters/remove-file-keeps-directory.var.new/stale.ngc", "G21 G90\n");
+    const staleDirectoryPath = simulator.fs.opfs.resolvePath("parameters/remove-file-keeps-directory.var.new");
+    await simulator.fs.opfs.readDirectory("parameters/remove-file-keeps-directory.var.new");
+    await simulator.fs.opfs.removeFile("parameters/remove-file-keeps-directory.var.new");
+    const staleDirectoryStat = await simulator.fs.opfs.stat("parameters/remove-file-keeps-directory.var.new");
+    if (staleDirectoryStat.kind !== "directory" || staleDirectoryStat.size !== null) {
+      throw new Error("OPFS removeFile removed a directory instead of preserving file-only semantics");
+    }
+    const staleDirectoryMode = simulator.fs.module.FS.stat(staleDirectoryPath).mode;
+    if (!simulator.fs.module.FS.isDir(staleDirectoryMode)) {
+      throw new Error("OPFS removeFile removed a WASM mirror directory instead of preserving file-only semantics");
+    }
+    await simulator.fs.opfs.removeDirectory("parameters/remove-file-keeps-directory.var.new");
+  });
 }