[FEATURE] Plan mode's 3rd option needs to auto-expand vertically as user provides multi-row input

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

On this screen:

 Claude has written up a plan and is ready to execute. Would you like to
 proceed?

 ❯ 1. Yes, auto-accept edits
   2. Yes, manually approve edits
   3. Tell Claude what to change
      shift+tab to approve with this feedback

 ctrl-g to edit in VS Code · ~/.claude/plans/sleepy-herding-dream.md

When typing into the input editor for option 3., The view only shows the first row of characters, even if the user provides multiple row's worth of input.

Proposed Solution

Ideal user experience, as we type, the line auto-wraps and makes room for the user's input, moving the 'shift+tab to approve with this feedback' line down, as the user's input occupies more and more lines.

Alternative Solutions

The current workaround is to scroll up to Option 2. When this happens, the entirety of the user's input on Option 3 is displayed. See additional context below.

Priority

Low - Nice to have

Feature Category

Interactive mode (TUI)

Use Case Example

Enter plan mode, and have claude create a plan.
Review the plan and notice a few issues with the plan.
On the prompt for plan approval, try to write extended feedback in the 'tell claude what to change' choice. The sentence being typed will be cut off when it reaches the end of the row and ellipses will appear after a while. Sometimes the input field will display a 2nd line of text, but more often than not, it only shows a single line and then displays ... at the end of the row.

Additional Context

<img width="578" height="167" alt="Image" src="https://github.com/user-attachments/assets/a2728d67-74d1-4bf5-9411-1e23a79e5a2c" />

Note: Scrolling up to choice 2. shows the user's input:

<img width="570" height="192" alt="Image" src="https://github.com/user-attachments/assets/a0399aef-78c6-4eae-be0f-5a8a3ff9404d" />