v2.4.68: Quick filter negation, upstream proxy bypass hosts, and UDP relay improvements

• Quick filter negation: Hold Alt/Option to negate filters from the context menu and toolbar
• Upstream proxy bypass hosts: Bypass hosts configuration and default port 8080 in upstream proxy settings
• Listener retry: Retry button when the listener fails to bind on startup

• UDP relay: Non-DNS UDP traffic is now relayed in transparent capture instead of being dropped
• KDE compatibility: Confirmation dialogs (save/discard) now render as in-app modals
• Firefox certificate installation: Attempts best effort when certutil is unavailable, with a clearer warning when certutil is required

• Linux transparent capture: No longer fails on first click after priming capabilities, and works with capabilities instead of requiring root
• UDP handling: Fixed multicast flow starvation, fake-IP relay issues, and memory and CPU spikes under heavy UDP traffic
• Modifier keys: Alt modifier no longer gets stuck when negating filters, and the label now shows 'Option' instead of 'Alt' on macOS

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Fluxzy Desktop 2.4.68 is available now for Windows, macOS, and Linux. Download it here.

Found a bug or have a feature request? Open an issue on GitHub.