feature: OpenCode v2 support

[oleastre]

Prerequisites

• I searched the docs
• I searched existing issues

Is your feature request related to a problem? Please describe.

OpenCode v2 is in beta, it seems the server API is changing.
I'm quite curious about testing that new version, but not without the nvim integration.

Describe the solution you'd like

This FR is a starting point to see if there is some interest trying to already port the plugin to v2 api.

Of course I can help implementing this, just maybe need some direction how this should be configured (configuration flag, new plugin branch, ... )

Describe alternatives you've considered

Alternatives:

• switch to an ACP based integration, not integrated in the same way as this plugin
• create a fork and implement the changes there

Additional context

No response

[nickjvandyke]

Thanks for tracking! Do you know what's changing? I hope it's just schema changes, and no loss of functionality. That would be easy to integrate.

just maybe need some direction how this should be configured (configuration flag, new plugin branch, ... )

I would lean towards no configuration. Keeps it simple and the plugin is stable so anyone stuck on OpenCode v1 has no urgent reason to upgrade both. iirc OpenCode's health endpoint might report its version? So if really necessary, we could check that at runtime and hide it completely from the user.

[oleastre]

The documentation is not really helpful on the changes: https://opencode.ai/v2/docs/migrate-v1/#server-api-and-clients
I will try to dig a bit in the rest API and in your plugin code to see what are the required functionalities.
At least the /heath endpoint should report "v2" (the returned object contains aversion field).
Good idea to auto-detect the version, if it can be made transparent, the switch will be easier.

[nickjvandyke]

Thank you! Check out server/init.lua. Everything is contained and abstracted there.