Added theme presets (Nord, Tokyo Night, Gruvbox, Catppuccin), GitHub activity heatmap, pet speech bubbles, CRT power-off effect, lock screen, achievement progress system
Added easter egg system with 12 achievements, pet daemon, disco mode, matrix rain, glitch sequence
Added interactive terminal with 30+ commands, virtual filesystem, command palette
Added floating windows, desktop apps (weather, code editor, file manager)
Added bilingual support (TR/EN), dark/light themes, sound effects
Initial release with desktop OS concept