🐛 Running Textual/TUI apps with run_in_background=true breaks terminal state

Problem Description

When Claude Code runs a Textual/TUI application using the Bash tool with run_in_background=true, it permanently breaks the terminal state, making the IDE unusable.

Steps to Reproduce

1. Have Claude Code run a Textual app (e.g., python3 app_textual.py)
2. Use run_in_background=true parameter in Bash tool
3. Terminal enters broken state with mouse tracking enabled
4. All mouse movements generate escape sequences like: <0;56;13M<0;56;13m

Technical Details

What happens:

• Textual apps activate alternate screen mode: \033[?1049h
• Enable mouse tracking: \033[?1000h, \033[?1003h, \033[?1015h, \033[?1006h
• When run in background, these terminal modes remain active
• Terminal becomes permanently broken until manual reset

Impact:

• User cannot type normally
• Mouse generates garbage characters
• IDE becomes unusable
• Requires terminal restart or manual stty sane + reset

Proposed Solutions

Option 1: Detect TUI apps

• Add heuristic to detect TUI/fullscreen apps
• Warn Claude before using run_in_background=true
• Suggest interactive execution instead

Option 2: Automatic cleanup

• Add cleanup handler to BashOutput tool
• Automatically send reset sequences when reading from TUI background process
• Restore terminal state after background job completion

Option 3: Documentation

• Add explicit warning in Bash tool documentation
• Provide examples of what NOT to do
• Suggest alternatives for testing UI apps

Workaround for Users

When terminal is broken:

stty sane
tput reset
printf '\033[?1049l\033[?25h\033[?1000l\033[?1003l\033[?1015l\033[?1006l'

Or simply: close the terminal tab and open a new one.

Environment

• OS: Linux (Ubuntu)
• Terminal: Claude Code integrated terminal
• Affected tools: Bash with run_in_background=true
• Affected apps: Any TUI framework (Textual, curses, py_cui, etc.)

Additional Context

This is a critical UX issue that makes Claude Code temporarily unusable. It would be great to have either:

1. Automatic detection and prevention
2. Automatic cleanup/recovery
3. Clear warnings in the tool documentation

Related frameworks affected:

• Textual
• py_cui
• curses
• npyscreen
• blessed
• asciimatics
• Any app using alternate screen buffer