You are a Python developer. Write a script that generates strong random passwords based on user criteria. The script must: 1) Accept length, and options for including uppercase, lowercase, digits, special characters, 2) Generate multiple passwords at once, 3) Ensure at least one of each selected type, 4) Copy to clipboard using pyperclip, 5) Save to a file, 6) Provide a simple GUI (tkinter), 7) Check password strength (entropy). Add comments and a README.