feat: implement game categories filter

[diiabblo]

Summary

Implements a comprehensive category filtering system allowing users to select specific trivia categories for personalized gaming experiences.

Changes

• Added category type definitions and constants for 10 categories
• Created useCategoryFilter and useCategoryStats custom hooks
• Implemented category UI components (CategoryCard, CategoryGrid, CategoryFilterHeader, SelectedCategoryTags, CategorySearch, CategoryStatsCard)
• Added localStorage utilities for persisting category preferences
• Created dedicated categories page with search and filter functionality
• Added comprehensive documentation

Categories Available

1. General Knowledge
2. Science
3. History
4. Sports
5. Entertainment
6. Geography
7. Art & Culture
8. Technology
9. Literature
10. Music

Features

• Multi-select category filtering
• Visual category cards with icons and colors
• Search functionality for quick category lookup
• Persistent user preferences via localStorage
• Category performance statistics tracking
• Responsive design for all screen sizes
• Selected category tags with remove functionality

Components Added

• CategoryCard: Individual category display with selection state
• CategoryGrid: Responsive grid layout for categories
• CategoryFilterHeader: Header with selection count and clear button
• SelectedCategoryTags: Removable tags for selected categories
• CategorySearch: Search input with real-time filtering
• CategoryStatsCard: Performance metrics per category

Closes #3