FR: Local Socks Proxy

### What are you trying to do?

Access the local network from a firefox container, while using an exit-node. For example, to configure a new router. In general, the local network would be temporary and should not be connected to the rest of the tailscale network.

### How should we solve this?

Provide a local socks proxy that is not subjected to the exit node, but instead to the default os routing.

### What is the impact of not solving this?

Yes, by disabling exit-node. And re-enabling it after working with the local network.

### Anything else?

_No response_