feat: set gemini-3-pro-preview as default model for plan agent

[usvimal]

Summary

• Set gemini-3-pro-preview (Google) as the default model for the plan agent

Change

The plan agent now has a default model configured:

model: {
  providerID: "google",
  modelID: "gemini-3-pro-preview",
},

This means when users switch to the plan agent, it will automatically use Gemini 3 Pro Preview instead of their default model.

Note

Users can still override this in their opencode.json config via the agent.plan.model setting.

[github-actions]

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[github-actions]

The following comment was made by an LLM, it may be inaccurate:

Based on my search, I found one potentially related PR:

Related PR:

• Add default variant config per agent - This PR deals with configuring default settings per agent, which is conceptually related to setting a default model for the plan agent.

However, this appears to be a different feature focused on variant configuration rather than specifically setting the model. The current PR (8728) is more focused on setting the default model provider/ID for the plan agent.

No exact duplicate PRs found addressing the same feature of setting gemini-3-pro-preview as the default model for the plan agent.