Consider accept prompt after `/plan`

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

May be just me beeing a noob, but I often type /plan and start defining the prompt without inserting a new line in between the two. Nothing happens other than entering plan mode, so then I have to press up and enter to get my prompt in it.

Does it make any sense to accept the two at once?

Proposed Solution

NA

Alternative Solutions

NA

Priority

Low - Nice to have

Feature Category

CLI commands and flags

Use Case Example

_No response_

Additional Context

_No response_