Feature request: respect terminal cursor shape in TUI input box

Summary

The Claude Code TUI input box renders a block cursor regardless of the host terminal's cursor shape setting. It should instead respect the terminal's configured cursor shape.

Motivation

My terminal (Ghostty) is configured to use a bar cursor everywhere, but Claude Code's input box overrides this with a block cursor, creating visual inconsistency with the rest of my terminal environment. Users who have already chosen a cursor style in their terminal shouldn't need a second setting to get the same style inside Claude Code.

Proposed solution

Rather than adding a new config option, have the TUI input box inherit/respect the terminal's cursor shape (bar, block, or underline) instead of forcing block. No new setting required — it just does the right thing by default.

Environment

• Terminal: Ghostty (configured with bar cursor)
• OS: macOS (Darwin 25.3.0)