- Add package.json with Vitest, jsdom, Vite, and Preact dependencies
- Configure Vitest with jsdom environment for component testing
- Create test stubs for billStore (PEOPLE-01, PEOPLE-02, PEOPLE-03, PEOPLE-04)
- Create test stubs for currency utilities (dollarsToCents, centsToDollars, formatCurrency)
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>