fix: Add proper type checking for NodeJS error code property

Address code review feedback by ensuring error.code is a string type

Co-authored-by: synthable <374893+synthable@users.noreply.github.com>

Author: Copilot

packages/ums-sdk/src/utils/file-utils.test.ts

@@ -30,6 +30,11 @@ describe('file-utils', () => {
       expect(isFileNotFoundError(error)).toBe(false);
     });
 
+    it('should return false for errors with non-string code property', () => {
+      const error = Object.assign(new Error('Error'), { code: 123 });
+      expect(isFileNotFoundError(error)).toBe(false);
+    });
+
     it('should return false for null', () => {
       expect(isFileNotFoundError(null)).toBe(false);
     });

packages/ums-sdk/src/utils/file-utils.ts

@@ -9,7 +9,12 @@ import { ModuleNotFoundError } from '../errors/index.js';
  * Type guard to check if an error is a NodeJS ErrnoException
  */
 function isNodeError(error: unknown): error is NodeJS.ErrnoException {
-  return error !== null && typeof error === 'object' && 'code' in error;
+  return (
+    error !== null &&
+    typeof error === 'object' &&
+    'code' in error &&
+    typeof (error as { code: unknown }).code === 'string'
+  );
 }
 
 /**