Feature Request: Connect TUI to Existing opencode serve Instance #878

Currently, running opencode serve starts the server on a specified port (e.g., 127.0.0.1:4096). However, there does not appear to be a way to connect the TUI to this running server instance. This would be useful for scenarios where I want to access logs or manage the server process separately.

Proposed Solution:
It would be helpful to support a command such as:

opencode --server 127.0.0.1:4096

or have opencode automatically connect to an existing local server if one is running, rather than starting a new instance.

Use Case:
This feature would allow users to:

• Run the server in headless mode (e.g., for logging or remote access)
• Connect multiple TUI clients to the same server instance
• Separate server and client processes for better control and observability

Request:
Is there currently a way to connect the TUI to an existing opencode serve instance? If not, could support for this workflow be added?

Thank you for your consideration!