Update ContextSection and TechStackSection with OAuth 2.0 and i18n features

- Replaced outdated features with 'OAuth 2.0 + Social Login' and 'i18n Ready' in ContextSection.
- Updated TechStackSection to include OAuth 2.0 (social login + provider mode) and next-intl (English, Italian) support.
- Refined descriptions in FeatureGrid and HeroSection to highlight new features.
- Improved messaging around OAuth and internationalization readiness across components.

frontend/src/components/home/HeroSection.tsx

@@ -46,7 +46,7 @@ export function HeroSection({ onOpenDemoModal }: HeroSectionProps) {
               />
               <span className="font-medium">MIT Licensed</span>
               <span className="text-muted-foreground">•</span>
-              <span className="font-medium">Comprehensive Tests</span>
+              <span className="font-medium">OAuth 2.0 + i18n</span>
               <span className="text-muted-foreground">•</span>
               <span className="font-medium">Pragmatic by Design</span>
             </div>