🎨 Enhance GitRecap badge styling and export functionality

[BrunoV21]

📝 Summary

This pull request introduces significant improvements to the GitRecap badge styling and export functionality, including a new 16:10 aspect ratio, enhanced visual design, and better customization options. The changes also include API refactoring and UI improvements for a more consistent and user-friendly experience.

✨ Features

• Added export functionality to save recap summaries as PNG images or HTML badges
• Implemented theme selector with dark, light, and default options for badge customization

🐞 Bug Fixes

• Fixed GitHub username assignment during PAT authorization
• Improved responsive design of the export modal to address mobile layout issues

⚙️ Improvements

• Updated badge design with a warm color scheme and improved layout
• Changed badge aspect ratio from 4:3 to 16:10 for better content presentation
• Enhanced text contrast and readability with adjusted line height and font sizing
• Refactored API to return username from store_fetcher and simplify external_signup response handling
• Improved button and UI element styling for better visibility and consistency
• Updated font family to Maus and added CDN link for better typography
• Enhanced visual consistency with updated gradient and background colors
• Replaced button elements with the Button component for better maintainability

🧹 Refactoring

• Wrapped dummyOutput in a div for improved styling and layout consistency
• Removed borders, border-radius, and box-shadow from theme selector and export option buttons

🗒️ Notes

• The changes focus on improving the visual appeal and usability of the badge export feature while maintaining consistency across the UI.