test: added test cases for MediaTypeWheel and MediaUploadComponent

Description:

Added comprehensive unit test coverage for MediaTypeWheel.tsx and MediaUploadComponent.tsx to improve reliability and maintainability of the application.

Created two new test files under tests/src/components/ with a total of 105 test cases:

• MediaTypeWheel.test.tsx (39 tests) covering rendering, selection behavior, callbacks, visual elements, accessibility, and edge cases.
• MediaUploadComponent.test.tsx (66 tests) covering all upload modes (document, text, audio, video, image), user interactions, conditional UI states, file handling, and edge scenarios.

Achieved:

• 100% statement coverage
• 100% line coverage
• ~99% branch coverage

The minor uncovered branch in MediaTypeWheel is due to a mathematically unreachable condition based on component design and does not indicate a testing gap.

Implemented robust testing patterns including:

• Mocking external dependencies (react-i18next, lucide-react, UI components, utilities, toast notifications)
• Simulating user events (clicks, input changes, uploads)
• Verifying callbacks using vi.fn()
• Testing conditional rendering for different modes and states (recording, camera active, file selected, etc.)
• Handling edge cases such as null values, empty inputs, missing callbacks, and invalid files

Additionally:

• Updated vitest.config.ts to include @ path alias for proper module resolution in tests
• Fixed all ESLint issues (e.g., using const, handling intentional any)
• Ensured all tests pass successfully with no warnings or errors

Commands used:

• npm run test:run -- tests/src/components/
• npm run test:coverage
• npm run lint -- tests/src/components/*.test.tsx

This significantly improves test coverage, reduces regression risk, and ensures confidence during future code changes.

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Type of Change:

• Bug Fix
• Feature Development
• Documentation

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Testing:

• Tested on desktop
• Tested on mobile
• Tested in different browsers

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Screenshots (if applicable):

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Checklist:

• Code follows project style guidelines
• Self-review completed
• No console errors
• TypeScript types are correct

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closes #249 (closed)