[FEATURE] Add support to customize claude code waiting screen

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

As a heavyweight Claude code user, I spent a lot of time waiting for Claude code to think (not a big fan of --dangerously-skip-permissions).

Therefore, if we can customize the waiting screen, instead of seeing Girbering..., we can play Star Wars in the terminal or anything waiting screen link. For example, like happy Claude code can preview a good movie.

There are a couple of other ideas, too, but the main idea is to let us customize the waiting screen. (can be ads placed in the future, but probably not that relevant)

Proposed Solution

I'd like to have ability to customize waiting screen and there are some prebuilt template (like star war).

Alternative Solutions

_No response_

Priority

Critical - Blocking my work

Feature Category

Interactive mode (TUI)

Use Case Example

Example scenario:

1. User writes a prompt
2. Claude start to thinking
3. Conclude this is a huge task
4. Watch a movie and wait

Additional Context

_No response_