Implement retro-themed styling and classic pixelated icons for the
archive browser when the "retro" theme is active.
Changes include:
- Adding CSS overrides for `[data-theme="retro"]` to style the archive
browser container, tree nodes, and hover states.
- Updating the JS preview script to dynamically append retro image
icons (e.g., classic shell32/zipfldr icons) alongside SVGs.
- Toggling visibility between SVG and retro image icons using CSS
based on the active theme.
Daniel Legt
a454e4239f
