Corrupted .claude.json causes PowerShell input duplication/echo

Description

When .claude.json gets corrupted (JSON Parse error: Unexpected EOF), PowerShell starts duplicating every keystroke and behaving erratically. The terminal becomes unusable until all Claude Code sessions are closed and the config is restored from backup.

Steps to reproduce

1. .claude.json becomes corrupted mid-session (truncated/incomplete JSON)
2. Claude Code detects corruption and prints backup restore instructions
3. PowerShell input starts echoing/duplicating every character typed
4. Issue persists across new terminal windows until config file is restored

Expected behavior

Corrupted config should not affect terminal input handling. Claude Code should gracefully handle the corruption without breaking the shell.

Workaround

Close all terminals, restore backup config, reopen:

copy "C:\Users\aagui\.claude\backups\.claude.json.backup.<timestamp>" "C:\Users\aagui\.claude.json"

Environment

• Windows 10 (MSYS_NT-10.0-26200)
• PowerShell + Git Bash (MSYS)
• Claude Code CLI