Allow configuring terminal cursor style (block/bar/underline)

Summary

Claude Code's TUI framework overrides the terminal's cursor style to a block cursor, ignoring user/system-level cursor preferences. Please expose a setting to configure the cursor shape.

Problem

When Claude Code launches, it switches into alternate screen mode and forces a block cursor regardless of the user's terminal configuration. Users who prefer a bar (vertical line) or underline cursor in their terminal have no way to carry that preference into Claude Code.

This affects all terminal hosts — Windows Terminal, VS Code integrated terminal, iTerm2, etc. — since the override happens at the TUI framework level.

Proposed Solution

Add a configurable setting, e.g.:

claude config set --global cursorStyle bar

With supported values: block, bar, underline (matching standard ANSI cursor shapes via \e[1-6 q escape sequences).

Alternatively, Claude Code could simply respect the terminal's existing cursor style rather than overriding it.

Environment

• OS: Windows 11 (also likely affects macOS/Linux)
• Terminal: PowerShell via Windows Terminal
• Claude Code version: latest