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

deploy/docker/Caddyfile

@@ -1,7 +1,38 @@
-# gooseek.ru — reverse proxy к web-svc
+# gooseek.ru, bait.su — reverse proxy
 # Caddy автоматически получает SSL от Let's Encrypt
+# Защита от DDoS: rate_limit (per-IP), лимит тела запроса
+#
+# Healthcheck Docker: запросы с 127.0.0.1 получают 200 без редиректа и без rate_limit,
+# иначе wget --spider падает на редиректе и autoheal постоянно перезапускает контейнер.
+http://127.0.0.1 {
+    respond 200
+}
 
 gooseek.ru, www.gooseek.ru {
+    request_body {
+        max_size 10MB
+    }
+    rate_limit {
+        zone per_ip {
+            key    {http.request.remote.host}
+            events 300
+            window 1m
+        }
+    }
     header Cache-Control "no-cache, no-store, must-revalidate"
     reverse_proxy web-svc:3000
 }
+
+bait.su, www.bait.su {
+    request_body {
+        max_size 10MB
+    }
+    rate_limit {
+        zone per_ip {
+            key    {http.request.remote.host}
+            events 300
+            window 1m
+        }
+    }
+    reverse_proxy ghost:2368
+}