Feature request: pin prompt input and status bar while scrolling conversation history

Summary

When scrolling up to read earlier conversation history in the Claude Code CLI, the prompt input area and status bar scroll off-screen. It would be a significant UX improvement to keep them pinned at the bottom of the viewport while the conversation content scrolls independently.

Current behaviour

The CLI uses standard readline-style rendering — the input and status line sit at the bottom of the terminal buffer. Scrolling up to review earlier output hides them entirely, requiring the user to scroll back down to type the next prompt.

Expected behaviour

The input area and status bar remain visible and interactive at the bottom of the terminal at all times, regardless of how far up the user has scrolled in the conversation.

Motivation / prior art

Google's Gemini CLI (antigravity) implements this: the conversation pane scrolls independently while the input + status region stays pinned. This is achievable in terminal CLIs using full TUI rendering libraries (e.g. ink, blessed, bubbletea) that reserve fixed screen regions rather than appending to the terminal buffer.

This feature would make it much easier to reference earlier context (error messages, code output, prior responses) while composing a follow-up prompt — a very common workflow when iterating on code changes.