Browser mode mocking doesn't work under directory with whitespaces

Describe the bug

The same code repro.test.ts and repro.ts are in bad dir and ok-dir.

// repro.test.ts
import { expect, test, vi } from 'vitest';

import { repro } from './repro';
vi.mock('./repro', { spy: true });

test('repro', () => {
  expect(vi.isMockFunction(repro)).toBe(true);
});

// repro.ts
export function repro() {}

Then mocking fails in bad dir:

$ npm run test
 ❯  chromium  test/bad dir/repro.test.ts (1 test | 1 failed) 4ms
   × repro 3ms
     → expected false to be true // Object.is equality
 ✓  chromium  test/ok-dir/repro.test.ts (1 test) 0ms

I'm not sure if this is an upstream issue on Vite. Maybe related to

• https://github.com/vitejs/vite/issues/15298
• https://github.com/vitejs/vite/issues/9917

Reproduction

https://stackblitz.com/edit/vitest-dev-vitest-gzxmzkqs?file=vite.config.ts

System Info

npmPackages:
    @vitest/browser: latest => 3.1.1 
    playwright: latest => 1.51.1 
    vitest: latest => 3.1.1

Used Package Manager

npm

Validations

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• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
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• The provided reproduction is a minimal reproducible example of the bug.

Start with the StackBlitz reproduction and the paired test/bad dir/repro.test.ts and test/bad dir/repro.ts files described in the report; compare them with the corresponding ok-dir files. Run the browser-mode test with the directory containing whitespace, trace how vi.mock resolves the module, and confirm that the mock is recognized there as it is in ok-dir.