Add a new "retro" theme option that mimics the classic Windows 98 aesthetic, providing a nostalgic alternative to the modern and classic dark themes.
Changes include:
- Defining CSS variables for the retro theme in `00-base.css` (pixel fonts, silver/gray colors, and classic window shadows).
- Adding custom styling for cards, headers, buttons, and title bars to replicate classic OS windows.
- Adding a star background GIF (`stars1.gif`).
- Excluding the retro theme from modern "revamp" styles in `15-revamp.css`.
- Updating `CLAUDE.md` with instructions on screenshot verification.
- Implement dynamic expiry options on the upload page based on user roles and retention policies.
- Add helper functions to build and format expiry options into human-readable labels.
- Introduce a new modern theme featuring glassmorphism, gradients, and frosted glass cards.
Modify the authentication handler to return an unauthorized error when
an invalid or disabled bearer token is provided, rather than silently
falling back to an anonymous request.
This ensures that clients attempting to authenticate but failing (due to
expired, malformed, or disabled tokens) are explicitly notified of the
auth failure instead of proceeding anonymously. True anonymous requests
without any Authorization header remain supported.
