Task 18: Category Navigation Pills on Homepage

Files modified:
- src/pages/index.astro
- src/pages/ru/index.astro
- src/i18n/translations.ts

Build result: PASS (85 pages, 0 errors)

Verification:
- dist/index.html contains category navigation pills
- dist/ru/index.html contains localized category navigation pills
- All 5 categories present: Gaming (6), Security (3), Decision Making (4), Creative (5), Utility (10)
- Links point to /generators/category/[category]/ (EN) and /ru/generators/category/[category]/ (RU)
- Pills styled with Tailwind: rounded-full, bg-zinc-800/60, border-zinc-700/50, hover:bg-accent/20, hover:text-accent
- Responsive flex-wrap layout