[FEATURE] Long Edit mode, submit doesn't send on ENTER

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

Often when typing a long prompt that needs multiple lines i'll prematurely trigger the submission by hitting enter OR mis-hitting Ctrl\Shift+Enter needing to use claude on mac or in parallels in windows.

Proposed Solution

/editmode or something that lets me just type, and ENTER just does a newline break and I can submit with a hotkey instead, like it's waiting for that impossible to accidentally trigger command.

Alternative Solutions

Typing it all out in an .md to reference, but then I have an .md to clean up.

Priority

Medium - Would be very helpful

Feature Category

CLI commands and flags

Use Case Example

I would live with this feature on, I trigger prompts accidentally all day long. Would let me worry about the prompt rather than pausing to wonder if its CTL+Enter or Shift+Enter and getting it wrong then needing to esc out and fix it all.

Additional Context

_No response_