[Feature Request] Add SSH Port Forwarding / Tunneling support

[gaetanbarras]

Hi! First of all, thanks for this great project.

I would love to see native support for SSH Port Forwarding (tunnels) directly in OmniSSH.

Currently, OmniSSH's terminal engine doesn't process LocalForward directives from ~/.ssh/config, and running SSH commands with -L options inside Snippets doesn't work because Snippets execute on the remote server instead of the local machine.

What I need:

• A way to define local port forwarding rules directly in the Host configuration UI (e.g. mapping localhost:9443 to remote 127.0.0.1:9443).
• Or automatic support for LocalForward rules configured in ~/.ssh/config.

This would make it super easy to access remote services (like Portainer or PostgreSQL databases) on localhost without having to run separate shell scripts outside OmniSSH.

Thanks!

[timhartmann7]

Folding #89 in here, and carrying over the requirement from its thread, because it is the most sizing-relevant sentence across both issues and would otherwise be lost:

"Multiple hosts are supported for tunnelling, and each host handles multiple
ports." — levlist, #89

Thanks for the issue!