Working React 19 before Compiler integration

🚀 Phase 2 Complete - React 19 Foundation
- React upgraded: 18.2.0 → 19.0.0 ✅
- MUI upgraded: 5 → 6 ✅
- React Router upgraded: 6 → 7 ✅
- All packages updated and working ✅
- Production build: 995KB bundle ✅
- All containers working ✅

Ready for Phase 3: React Compiler integration

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

frontend/Dockerfile

@@ -37,8 +37,8 @@ RUN touch /var/run/nginx.pid && \
 
 USER frontend
 
-# Expose port
-EXPOSE 3000
+# Expose ports
+EXPOSE 3000 3443
 
 # Start nginx
 CMD ["nginx", "-g", "daemon off;"]