[BUG] Voice dictation input not cleared after sending message in Desktop app

Bug Description

After sending a message that was composed using voice dictation in the Claude Code Desktop app, the transcribed text remains in the input box instead of being cleared. The user must manually delete the previous text before dictating again.

This does not happen in the VS Code extension — the input clears correctly on send there.

Steps to Reproduce

1. Open Claude Code Desktop app
2. Enable voice dictation (click the mic/dictation button)
3. Speak a prompt — text gets transcribed into the input box
4. Send the message (press Enter or click send)
5. Expected: input box clears, ready for next message
6. Actual: transcribed text remains in the input box; must be manually deleted before next dictation

Environment

• Claude Code version: 2.1.179
• Platform: Windows (Desktop app)
• Voice mode: hold mode (default)

Additional Context

• Works correctly in VS Code extension (input clears after send)
• Using keyboard shortcut instead of clicking the mic button does not change the behavior
• Happens consistently on every voice-dictated message
• Workaround: manually select all and delete before each new dictation session

Impact

Makes voice dictation in the Desktop app significantly more friction-heavy than in VS Code, effectively requiring a manual cleanup step after every single message.