test(client): add Vitest and React Testing Library setup

[NishaKhandelwal]

📋 What does this PR do?

This PR sets up frontend testing for the FitMart client using Vitest and React Testing Library.

Changes made:

• Configured Vitest for the Vite React application.

• Added a global test setup file (src/test/setup.js).

• Added utility tests for:

  • healthUtils
  • normalizeProduct

• Added an initial render test for the FitnessChatBot component.

• Updated the GitHub Actions CI workflow to execute frontend tests during pull requests.

Note: While setting up the testing environment, I encountered dependency version conflicts in the existing project (@eslint/js and @vitejs/plugin-react) that prevented a clean installation. I updated those dependency versions locally so the project could install successfully and the testing setup could be implemented.

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🔗 Related Issue

Closes #

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🧪 How was this tested?

• Installed project dependencies successfully.
• Ran the frontend test suite locally using:

npm test

• Verified that all tests pass successfully.
• Confirmed that the GitHub Actions workflow includes the frontend test step.

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📸 Screenshots (if UI changes)

No UI changes were made.

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✅ Checklist

• I've read the CONTRIBUTING guide
• My code follows the project's style guidelines
• I've tested my changes locally
• I've linked the related issue
• I haven't introduced any new secrets or API keys