v1.1.1

Bug Fixes

• Fixed a bug in EnigmaMachine._next_letter() where str.upper() was called but the result was never assigned, making it a no-op for lowercase input.
• Removed unused imports (math.e in rotor.py, re in reflector.py).

Testing

• Added 43 property-based fuzz tests using hypothesis covering rotor bijectivity, reflector involution, plugboard symmetry, and reciprocal encryption across thousands of randomized configurations.