- redesign password generator UI with modern styling and responsive layout

- add new features:
  - password presets (basic, strong, ultra)
  - visual strength meter with percentage indication
  - password visibility toggle
  - custom symbols input field
  - exclude similar characters option (1lI0O)
  - ensure minimum requirements toggle
- improve password generation algorithm:
  - better character distribution
  - string shuffling for randomness
  - more accurate strength calculation
- enhance UX with tooltips, visual feedback, and one-click actions

Author: TobiasMue91