Feature request: Visually distinguish user input from assistant output

Problem

In long Claude Code sessions, it's difficult to scroll back and find where my own messages are. User input and assistant output blend together visually, making it hard to navigate the conversation history.

Suggested Solution

Render user input lines with a distinct visual treatment — for example:

• A different background color or subtle highlight bar
• A colored left border/gutter
• Bold or differently-colored prompt indicator

This would make it easy to scan scrollback and locate where each user message starts.

Context

Terminal emulators like Ghostty support jump_to_prompt via shell integration (OSC 133), but this only works for shell prompts — not for input lines within Claude Code's TUI. So there's no terminal-level workaround; this needs to be handled by Claude Code's own rendering.

Alternatives Considered

• Terminal themes/colors — these apply globally, not per-message
• Ghostty jump_to_prompt — only marks shell prompts, not Claude Code's internal input lines
• /theme command — changes overall color scheme but doesn't differentiate user vs assistant