refactor(codebase): enhance application codebase

[devmeireles]

What's Changed

This PR introduces several enhancements to improve the codebase's maintainability, readability, and functionality. Here's a summary of the changes:

1. State Management with Zustand:

   • Integrated Zustand for centralized and efficient state management.

   • Added persistent storage to ensure the application state is preserved across page reloads.

2. Component Refactoring:

   • Split larger components into smaller, reusable, and maintainable pieces.

   • Improved folder structure for better organization and scalability.

3. Styling Enhancements:

   • Updated and standardized styles using a consistent design system.

   • Improved UI/UX for better user interaction.

4. TypeScript Enhancements:

   • Fixed TypeScript errors and added proper type definitions.

   • Introduced enums and interfaces for better type safety and readability.

5. Testing:

   • Added comprehensive unit tests to ensure code reliability.

   • Achieved 100% test coverage for all critical components and logic.

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How to Test

To verify the changes, follow these steps:

1. Run the Application:

   • Start the development server:

     pnpm run dev

   • Navigate to the application in your browser and interact with the task manager to ensure everything works as expected.

2. Run Tests:

   • Execute the test suite to ensure all functionality is covered:

     pnpm test

   • Run tests in watch mode during development:

     pnpm run test:watch

   • Generate a coverage report to verify 100% test coverage:

     npm run test:coverage

3. Verify Persistent Storage:

   • Add some tasks, refresh the page, and ensure the tasks are still present.

   • Change the filter state, refresh the page, and verify that the filter state is preserved.