Feature request: Add opencode server URL as environment variable

[TheStaticMage]

It would be handy to have the OpenCode server URL easily available in the OpenCode environment. For me personally I'm making API calls from tools and plugins to the OpenCode server to accomplish things that aren't currently supported by their plugin architecture. Being able to identify the "correct" OpenCode server to talk to is important for this use case.

✔️ You already provide OPENCODE_SERVER_USERNAME and OPENCODE_SERVER_PASSWORD in the environment.
❌ The OpenCode server port is not available in the environment.

Request: Add something like OPENCODE_SERVER_BASE_URL with the full URL and/or OPENCODE_SERVER_PORT with the port number in the environment.

My current workaround is to use CODENOMAD_INSTANCE_ID + CODENOMAD_BASE_URL to look this up in CodeNomad's API. However this is an extra API call that might require auth, etc.

[shantur]

@TheStaticMage - CodeNomad doesn't know what port opencode will start on as it selects a random available port to ensure there aren't port clashes between multiple opencode instances. So the only way is to use CodeNomad API to be able to talk to opencode.
For opencode plugins, you can internally use the OpenCode SDK. For tools you will need to either go via CodeNomad API or check what port opencode is running on via OS calls maybe.