[BUG] Cmd+D voice dictation stops working after first response (Desktop app)

Bug Description

Voice dictation via Cmd+D works on the first message of a conversation but stops responding after Claude gives its first response. The microphone is clearly connected since the initial dictation succeeds.

Steps to Reproduce

1. Open Claude Code desktop app
2. Press Cmd+D — voice dictation activates and works correctly
3. Submit the message and wait for Claude's response
4. Press Cmd+D again — nothing happens, dictation does not activate
5. Clicking into the input field and retrying Cmd+D does not help
6. Toggling /voice off/on does not resolve it

Expected Behavior

Cmd+D should activate voice dictation on every press, not just the first message.

Environment

• Claude Code version: 2.1.37
• Platform: Desktop app (macOS)
• macOS version: 26.3.1
• Microphone: Working (confirmed by successful first dictation)