Add dark mode to chat sample application

[orsharon7]

Feature Request: Add Dark Mode to Chat Sample Application

Summary

Implement a dark mode theme for the chat sample application to improve usability and aesthetics for users who prefer a dark interface.

Details

• Add a toggle option to switch between light and dark mode.
• Ensure all UI components adapt to the selected theme.
• Update stylesheets or use CSS variables for theme management.
• Test across all major browsers to ensure consistent appearance.

Benefits

• Enhances accessibility, especially in low-light environments.
• Provides a modern look and feel.
• Aligns with user expectations for contemporary web applications.

Additional Notes

• Consider providing options for automatic theme switching based on system preferences.

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Assigned to: github coding agent
Repository: orsharon7/github-copilot-masterclass