feat: Go backend, enhanced search, new widgets, Docker deploy

Major changes:
- Add Go backend (backend/) with microservices architecture
- Enhanced master-agents-svc: reranker, content-classifier, stealth-crawler,
  proxy-manager, media-search, fastClassifier, language detection
- New web-svc widgets: KnowledgeCard, ProductCard, ProfileCard, VideoCard,
  UnifiedCard, CardGallery, InlineImageGallery, SourcesPanel, RelatedQuestions
- Improved discover-svc with discover-db integration
- Docker deployment improvements (Caddyfile, vendor.sh, BUILD.md)
- Library-svc: project_id schema migration
- Remove deprecated finance-svc and travel-svc
- Localization improvements across services

Made-with: Cursor

services/web-svc/next.config.mjs

@@ -49,7 +49,7 @@ const nextConfig = {
   async rewrites() {
     const gateway = process.env.API_GATEWAY_URL ?? 'http://localhost:3015';
     return [
-      { source: '/api/chat', destination: `${gateway}/api/chat` },
+      // /api/chat handled by app/api/chat/route.ts for proper streaming support
       { source: '/api/v1/:path*', destination: `${gateway}/api/v1/:path*` },
       { source: '/api/config', destination: `${gateway}/api/v1/config` },
       { source: '/api/config/:path*', destination: `${gateway}/api/v1/config/:path*` },