Main Menu graphics settings

[blontd6]

Is your feature request related to a problem? Please describe.
Players currently cannot configure their graphics settings from the main menu. They have to wait until they start or join a match to adjust settings. Additionally, there is no way to export or backup custom graphics settings to easily share or load them.

Describe the solution you'd like

1. Add a "Graphics Settings" option in the main menu settings modal so players can configure their visual preferences beforehand.
2. Include "Export settings" and "Import settings" buttons inside the Graphics Settings modal to let players download their settings as a JSON file and upload them later.

Describe alternatives you've considered
Manually editing values or having to adjust graphics settings from scratch at the start of every game session.

Additional context
Adding these options allows players to pre-configure and share setups before loading maps.

[github-actions]

Hi @blontd6, thanks for opening this issue. It hasn't been approved by a maintainer yet — we'll get back to you shortly to either milestone it (approval) or close it.

— Automated. See CONTRIBUTING.md.