Desktop app: partial text selection copies entire message instead of highlighted portion

Environment

• App: Claude Code Desktop
• OS: Windows 11 Pro

Steps to reproduce

1. Open any conversation in Claude Code Desktop
2. Click and drag to highlight a partial sentence within an assistant message
3. Press Ctrl+C (or Ctrl+Shift+C)

Expected

Only the highlighted text is copied to the clipboard.

Actual

The entire message block is copied, regardless of what's highlighted.

Things I tried

• Ctrl+C — copies the whole message
• Ctrl+Shift+C — same behaviour
• Shift+drag selection — same behaviour

Impact

Forces switching to claude.ai/code in a browser whenever I need to quote a fragment of a Claude response in another tool. Selection works normally in the web version, so this is specific to the desktop app.