Proposal: Add Full Application & Downloader Network Interface / VPN Binding

[Crazymace12]

Currently, Fit-Launcher and its background downloader bind to the host's default network. I think a lot of users in the community would benefit from being able to force all application network traffic to route through a specific network adapter, like a VPN.

How it could work:

In the app settings, provide a dropdown that lists all available host network adapters so the user can select their VPN interface, or if need be allow users to manually enter an IPv4 address to route traffic through.

The selected network adapter would be used for both the main launcher (for fetching metadata and cover images) and the background downloader (aria2c), so traffic doesn't leak over the main home connection if a VPN drops or if split-tunneling is active.