Task 20: RelatedGenerators.astro

Files changed:
- src/components/RelatedGenerators.astro (created)
- src/layouts/GeneratorLayout.astro (updated — integrated RelatedGenerators)
- src/i18n/translations.ts (updated — added relatedGenerators key EN+RU)

Build result:
- npm run build: PASSED
- 76 pages built, 0 errors

Component behavior:
- Accepts props: currentSlug, category, optional lang
- Filters generators by category, excludes current slug, limits to 4
- Returns null (renders nothing) if no related generators exist
- Locale-aware titles and links (EN / RU)
- Compact card layout: icon + title in a responsive 2-column grid
- Uses Tailwind with existing design tokens (accent color, zinc palette)
- Includes focus-visible ring for accessibility
