New workflow:
1. User runs: source run.sh (instead of bash launcher.sh)
2. Launcher runs normally
3. On exit with cleanup=yes, launcher sets flag file
4. Wrapper detects flag and does ALL cleanup automatically:
- Cleans ~/.bash_history file
- Clears current shell's in-memory history
- Removes toolkit directory
- No manual commands needed
The key: wrapper is SOURCED so it runs in parent shell and can modify history.
User experience: answer "yes" and cleanup happens instantly, automatically.