test(desktop): match the desktop.mjs compile step with native path separators

The --icons case found the compile command with endsWith('/scripts/build/desktop.mjs'),
which never matches the path.join-built argument on Windows, so the case failed with
TypeError instead of asserting. Match both separator styles.

Fixes https://github.com/NousResearch/hermes-agent/issues/125139

tests-js/desktop-builder.test.mjs

@@ -18,7 +18,8 @@ test('desktop development composition reuses prepared icon pixels instead of pro
     run: (command, args) => commands.push([command, ...args]),
   })
   expect(readFileSync(join(input.source, 'apps/desktop/assets/icon.ico'), 'utf8')).toBe('prepared packaging icon')
-  const compile = commands.find(command => command.some(arg => arg.endsWith('/scripts/build/desktop.mjs')))
+  // path.join builds platform-native separators, so accept both `/` and `\`.
+  const compile = commands.find(command => command.some(arg => /[/\\]scripts[/\\]build[/\\]desktop\.mjs$/.test(arg)))
   expect(compile[compile.indexOf('--icons') + 1]).toBe(input.icons)
 })
 afterEach(() => { for (const root of roots.splice(0)) rmSync(root, { recursive: true, force: true }) })