test(ui): improve main UI's components tests

[luizhf42]

This PR significantly enhances test coverage across the application's main UI components, adding comprehensive test suites that validate component behavior, user interactions, error handling, and edge cases. The improvements establish a stronger testing foundation for the frontend codebase.

Robust test coverage is essential for maintaining code quality as the application evolves. These improvements:

• Increase confidence in component behavior and catch regressions early
• Serve as living documentation for component APIs and expected behaviors
• Make refactoring safer by ensuring existing functionality remains intact
• Establish consistent testing patterns for future component development

This branch adds and improves tests for core UI components across multiple areas. All tests follow consistent patterns with proper mocking, isolation, and cleanup to ensure maintainability.

Impact

• Significantly increased test coverage for critical UI components
• Established testing patterns that can be replicated across other components
• Improved confidence in component reliability and maintainability
• No breaking changes to existing functionality