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/discover-svc/package.json

@@ -13,9 +13,11 @@
     "fastify": "^4.28.1",
     "@fastify/cors": "^9.0.1",
     "ioredis": "^5.4.1",
-    "zod": "^3.23.8"
+    "zod": "^3.23.8",
+    "better-sqlite3": "^11.9.1"
   },
   "devDependencies": {
+    "@types/better-sqlite3": "^7.6.12",
     "@types/node": "^22.10.0",
     "tsx": "^4.19.2",
     "typescript": "^5.7.2"