[BUG] Terminal repaint ghosting after window resize (Windows Terminal / PowerShell)

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

After manually resizing the Windows Terminal window once during a session, subsequent UI redraws (e.g. when switching between agents/subagents) leave stale content on screen instead of fully repainting. Old box content from a previous render (e.g. a prior agent's input box) stays visible, overlapping the new render, until another manual window resize forces a full repaint.

This does not happen before any resize occurs in the session — the TUI renders correctly from a fresh session start until the window is manually resized once.

What Should Happen?

The TUI should fully repaint the affected screen region on every redraw (e.g. on agent switch), regardless of whether the terminal window has been manually resized earlier in the session. No stale content from a previous render should remain visible.

Error Messages/Logs

N/A — this is a visual rendering bug, not an error/exception. See attached screenshots showing a stale input box ("ai schedule generation timeout") overlapping the current one.

Steps to Reproduce

1. Open Windows Terminal (PowerShell profile) and start a claude session.
2. Use Claude Code normally for a while without resizing the window — rendering is correct.
3. Manually resize the Windows Terminal window (e.g. drag a corner slightly), then return focus to the session.
4. Continue using Claude Code, triggering a redraw where the new content differs from what was previously on screen (e.g. switching between agents/subagents).
5. Observe: stale content from a previous render remains on screen, overlapping the new render.
6. Resizing the window again forces a full repaint and temporarily "fixes" the display — until the next redraw after that.

Already ruled out while investigating:

• Not a conhost/legacy-console issue — confirmed running in actual Windows Terminal (not "Windows PowerShell" console host).
• Windows Terminal Settings → Rendering → "Disable partial Swap Chain invalidation" — enabled, restarted Terminal, issue persisted.
• Not a stale-CLI-version issue — claude --version matches the latest version published on npm.

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.220 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

Confirmed on Windows Terminal with hardware-accelerated rendering (Graphics API: Automatic). Screenshots attached show the exact glitch: a previous agent's rendered input box remains on screen, overlapping the current one, after a resize + agent-switch sequence.