2.1.0: Refactor project display using image cards

Replace itch.io embeds on Games and Apps pages with a new responsive
card component that uses project images.

Split the Music page content into 'Divin' and 'Karasu-san' sections
based on updated config structure. Add new 'Brasil' track.

Add docstrings to components and page functions. Update dependencies,
including Reflex to 0.7.9.