Model selection in /command incorrectly changes the default model #8452

Bug Description

When executing a /command that specifies a different model than the current default, after the command completes, the default model setting is incorrectly changed to the model specified in the command.

Steps to Reproduce

1. Select a default model (e.g., glm-4.7) in OpenCode settings
2. Use a /command that specifies a different model with open subtask: true, for example:

   /command zhipuai-coding-plan/glm-4.6 open subtask: true
   

3. Wait for the command to finish running
4. Check the default model setting

Expected Behavior

The default model should remain as glm-4.7 (the originally selected model). The model specified in the command (glm-4.6) should only be used for that specific subtask execution.

Actual Behavior

The default model setting changes from glm-4.7 to glm-4.6 after the command completes.

Impact

Users lose their preferred default model setting when using commands that specify different models, requiring them to manually reset their preferred model after each command execution.

Environment

• OpenCode (1.1.19)

Ref

• fix: prevent subagent model changes from persisting to parent #6668