[Feature Request] Desktop app needs configurable Return key behavior for multiline input

Bug Description

1. No option to make Return insert a new line (and Cmd+Return send) in the desktop app's message box, as the CLI allows. 2. Switching between the CLI and the desktop app on the same session lost context: the desktop showed only the pre-CLI messages, although the transcript file had all of them. Session 0b5c42f6-51b5-4eec-a28d-a24fa25547cd.

Environment Info

• Platform: darwin
• Terminal: Apple_Terminal
• Version: 2.1.288
• Feedback ID: 0db1352a-c749-407f-ba24-530202bcac1e