Accept service routes and allow other tunnels

[vkz]

NB: I patched it for myself in the fork - enough for me. Please close if unwanted or redo - I don't need credit. My usecase maybe too weird 🤷

Problem

Machine:

• Mac not on tailnet and can't be because IP ranges conflict with Cloudflare ;
• must be able to reach Tailscale services yes services not just nodes.

Issues with upstream ts-unplug-proxy:

• on Mac tsnet auto binds en0 ignores (correctly) utun0 to avoid looping, but
• it is being wrong when you know for sure it is a different overlay with default route. Must be an opt-in switch to allow when you know what you're doing.
• wasn't accepting advertised service routes;
• strange name resolution where it tried to be clever and resolve to host not service on conflict instead of consulting TS DNS.

Summary

• Add -disable-interface-binding an opt-into competing tunnels like Cloudflare WARP.
• Add opt-in -accept-routes.
• Prefer Tailscale DNS over peer aliases so Service VIPs resolve correctly.

CLOSE me if don't care