Add configurable Opencode server/port address for attaching to Opencode server running from a container #294

I'm interested in sandboxing the Opencode server in a Docker container in order to run YOLO mode with less inherent risk. I've gotten Opencode sandboxed in a Docker container, but I'm wanting to run Neovim from the host machine for better performance (instead of within the container as well).

Right now, this plugin starts the server and connects to the Opencode instance. However, I wonder if you've considered a configuration option that would let you connect to another running instance? I think this way I could use Neovim on the host machine while sandboxing the Opencode instance.

Using the plugin as-is works inside the container, but I've seen some performance degradation and it's difficult to ensure all my other environment configurations (for a project and for Neovim) are functioning as expected within a container. I'd much rather run my native host Neovim session and connect to the sandboxed Opencode server.

There have also been some security concerns surrounding the bare Opencode server, so this proposed update could provide a valid workaround— see the article here: https://cy.md/opencode-rce/