[BUG] Refusal response is hidden and conversation history disappears (OpenCode Go)

Description

While using muse-spark-1.2-contributor through an OpenCode Go subscription, a run can finish without showing any response or error in the UI. In other occurrences, the run remains active indefinitely.

In the captured occurrence, the HTTP stream completed successfully and contained a refusal message:

event: response.completed
data: {"response":{"status":"completed","error":null,"output":[{"role":"assistant","content":[{"type":"refusal","refusal":"I'm sorry, but I can't help with that request."}]}]}}

OpenCode did not display that refusal or any error. The conversation view became empty, previous messages were no longer visible, and /revert could not recover them.

This report is about how OpenCode presents and preserves the session after this response. It does not assume why the model returned a refusal.

Steps to Reproduce

1. Use muse-spark-1.2-contributor with an OpenCode Go subscription.
2. Continue an existing conversation and send a prompt.
3. Encounter a response containing a refusal content block.

Actual Behavior

• The run may end with no visible response or error, or remain active indefinitely.
• The refusal returned by the provider is not shown.
• The conversation view becomes empty and previous messages disappear.
• /revert cannot recover the missing conversation.

Expected Behavior

• OpenCode shows the provider response or a visible error.
• Existing conversation history remains available.
• The session reaches a clear completed or failed state.

Environment

• OpenCode: 1.18.22
• Provider: OpenCode Go subscription
• Model: muse-spark-1.2-contributor
• OS: macOS

Screenshot

The conversation area is empty after the run, with no refusal or error shown: