fix(deps): add missing @opencode-ai/plugin to dependencies

[HelloGGX]

Description

This PR fixes a Cannot find module error encountered when running tools that rely on @opencode-ai/plugin.

The Problem

As described in issue #2802, running scripts like .opencode/tool/github-triage.ts fails with the following error because the plugin package was missing from the dependencies list:

error: Cannot find module '@opencode-ai/plugin' from ...

The Fix

I have added "@opencode-ai/plugin": "workspace:*" to the dependencies section in package.json. This ensures the module is correctly linked and available for the tools to use.

Related Issue

Fixes #2802

[rekram1-node]

Btw this won't fix that persons issue, they had an in general request for:

allow running custom tools without external dependencies

That would mean no requirement of this dep at all (not possible rn)

ALso if u run opencode in opencode repo itll auto install this dep, so idk if we need to include in root package.json?