[BUG] Claude Desktop Code mode: Response completes but UI doesn't render until user sends new message

Description

In Claude Desktop Code mode, sessions intermittently stall where the response appears to complete (spinner disappears) but no output is rendered. Only the user's last message is visible. Typing a new message triggers the previous response to appear.

This is similar to the Cowork rendering bug (#26805, fixed Feb 25) but occurs in Code mode, suggesting the underlying UI flush issue was not fully resolved or has regressed.

Steps to Reproduce

1. Use Claude Desktop in Code mode with MCP tools active
2. Send a prompt that triggers tool use
3. Intermittently, the response completes but the UI shows no update
4. Spinner is no longer visible, no error shown
5. Sending any new message causes the missing response to render

Expected Behaviour

Responses should render as they stream, without requiring user interaction to trigger display.

Environment

• macOS (Apple Silicon)
• Claude Desktop (latest, March 2026)
• Code mode (not Cowork)
• Multiple MCP servers active (Claude in Chrome, Control Chrome, n8n, WordPress.com, etc.)

Related Issues

• #26805 (Cowork rendering bug, closed/fixed Feb 25)
• #28188 (Code mode stuck on Thinking, closed)