GUI Release — Tkinter interface & refactor

Added

• Tkinter GUI (gui.py) with:
  • Length slider (4–50)
  • Checkboxes for digits, lowercase, uppercase, symbols, special chars
  • Generate button + Copy to clipboard
  • Input validation and status messages
• Shared generation engine in password_generator.py
• Console app (cli.py) now uses the same engine

Initial Stable Release

🔐 Initial stable version of the Password Generator project.

This version includes:

✅ User-defined password length (between 4 and 50)
✅ Optional inclusion of:

• Lowercase letters
• Uppercase letters
• Digits
• Special characters
  ✅ Randomized and secure password generation
  ✅ Input validation with error handling
  ✅ Clean and beginner-friendly code structure

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🛠️ Future improvements (planned):

• Add unit tests
• Copy to clipboard (or other solution)