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

backend/deploy/docker/Dockerfile.all

@@ -0,0 +1,50 @@
+# Multi-service Dockerfile - builds all services
+FROM golang:1.22-alpine AS builder
+
+RUN apk add --no-cache git ca-certificates
+
+WORKDIR /app
+
+COPY go.mod go.sum ./
+RUN go mod download
+
+COPY . .
+
+# Build all services
+RUN CGO_ENABLED=0 GOOS=linux go build -ldflags="-s -w" -o /bin/api-gateway ./cmd/api-gateway
+RUN CGO_ENABLED=0 GOOS=linux go build -ldflags="-s -w" -o /bin/agent-svc ./cmd/agent-svc
+RUN CGO_ENABLED=0 GOOS=linux go build -ldflags="-s -w" -o /bin/chat-svc ./cmd/chat-svc
+RUN CGO_ENABLED=0 GOOS=linux go build -ldflags="-s -w" -o /bin/search-svc ./cmd/search-svc
+RUN CGO_ENABLED=0 GOOS=linux go build -ldflags="-s -w" -o /bin/llm-svc ./cmd/llm-svc
+RUN CGO_ENABLED=0 GOOS=linux go build -ldflags="-s -w" -o /bin/scraper-svc ./cmd/scraper-svc
+RUN CGO_ENABLED=0 GOOS=linux go build -ldflags="-s -w" -o /bin/discover-svc ./cmd/discover-svc
+RUN CGO_ENABLED=0 GOOS=linux go build -ldflags="-s -w" -o /bin/collection-svc ./cmd/collection-svc
+RUN CGO_ENABLED=0 GOOS=linux go build -ldflags="-s -w" -o /bin/file-svc ./cmd/file-svc
+RUN CGO_ENABLED=0 GOOS=linux go build -ldflags="-s -w" -o /bin/thread-svc ./cmd/thread-svc
+RUN CGO_ENABLED=0 GOOS=linux go build -ldflags="-s -w" -o /bin/computer-svc ./cmd/computer-svc
+RUN CGO_ENABLED=0 GOOS=linux go build -ldflags="-s -w" -o /bin/finance-heatmap-svc ./cmd/finance-heatmap-svc
+RUN CGO_ENABLED=0 GOOS=linux go build -ldflags="-s -w" -o /bin/learning-svc ./cmd/learning-svc
+RUN CGO_ENABLED=0 GOOS=linux go build -ldflags="-s -w" -o /bin/labs-svc ./cmd/labs-svc
+RUN CGO_ENABLED=0 GOOS=linux go build -ldflags="-s -w" -o /bin/podcast-svc ./cmd/podcast-svc
+RUN CGO_ENABLED=0 GOOS=linux go build -ldflags="-s -w" -o /bin/browser-svc ./cmd/browser-svc
+
+# Runtime stage
+FROM alpine:3.19
+
+RUN apk add --no-cache ca-certificates tzdata
+
+WORKDIR /app
+
+COPY --from=builder /bin/* /app/
+
+# Default entrypoint - can be overridden
+ENV SERVICE=api-gateway
+ENV PORT=3015
+
+EXPOSE 3015 3018 3005 3001 3020 3021 3002 3025 3026 3027 3030
+
+HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
+    CMD wget --no-verbose --tries=1 --spider http://localhost:${PORT}/health || exit 1
+
+# Run the specified service
+CMD /app/${SERVICE}