Configure Vitest and the test environment

[sawaymas]

Description:

• Set up the necessary testing tools for React components.

Tasks:

• Install Vitest.
• Install React Testing Library.
• Install jest-dom.
• Configure jsdom.
• Create a test setup file.
• Add a test command to package.json.

Acceptance:

• npm run test works.
• A simple example test passes.
• React components can be rendered in the test environment.