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/internal/agent/researcher.go

@@ -0,0 +1,128 @@
+package agent
+
+import (
+	"context"
+
+	"github.com/gooseek/backend/internal/llm"
+	"github.com/gooseek/backend/internal/search"
+	"github.com/gooseek/backend/internal/session"
+	"github.com/gooseek/backend/internal/types"
+	"github.com/google/uuid"
+)
+
+type ResearchInput struct {
+	ChatHistory      []llm.Message
+	FollowUp         string
+	Classification   *ClassificationResult
+	Mode             Mode
+	Sources          []string
+	Locale           string
+	DetectedLang     string
+	IsArticleSummary bool
+}
+
+func research(
+	ctx context.Context,
+	sess *session.Session,
+	llmClient llm.Client,
+	searchClient *search.SearXNGClient,
+	input ResearchInput,
+) ([]types.Chunk, error) {
+	maxIterations := 1
+	switch input.Mode {
+	case ModeBalanced:
+		maxIterations = 3
+	case ModeQuality:
+		maxIterations = 10
+	}
+
+	researchBlockID := uuid.New().String()
+	sess.EmitBlock(types.NewResearchBlock(researchBlockID))
+
+	allResults := make([]types.Chunk, 0)
+	seenURLs := make(map[string]bool)
+
+	searchQuery := input.Classification.StandaloneFollowUp
+	if searchQuery == "" {
+		searchQuery = input.FollowUp
+	}
+
+	for i := 0; i < maxIterations; i++ {
+		queries := generateSearchQueries(searchQuery)
+
+		sess.UpdateBlock(researchBlockID, []session.Patch{
+			{
+				Op:   "replace",
+				Path: "/data/subSteps",
+				Value: []types.ResearchSubStep{
+					{
+						ID:        uuid.New().String(),
+						Type:      "searching",
+						Searching: queries,
+					},
+				},
+			},
+		})
+
+		for _, q := range queries {
+			resp, err := searchClient.Search(ctx, q, &search.SearchOptions{
+				Categories: categoriesToSearch(input.Sources),
+				PageNo:     1,
+			})
+			if err != nil {
+				continue
+			}
+
+			for _, r := range resp.Results {
+				if r.URL != "" && !seenURLs[r.URL] {
+					seenURLs[r.URL] = true
+					allResults = append(allResults, r.ToChunk())
+				}
+			}
+		}
+
+		if input.Mode == ModeSpeed {
+			break
+		}
+
+		if len(allResults) >= 20 && input.Mode == ModeBalanced {
+			break
+		}
+
+		if len(allResults) >= 50 {
+			break
+		}
+	}
+
+	return allResults, nil
+}
+
+func categoriesToSearch(sources []string) []string {
+	if len(sources) == 0 {
+		return []string{"general", "news"}
+	}
+
+	categories := make([]string, 0)
+	for _, s := range sources {
+		switch s {
+		case "web":
+			categories = append(categories, "general")
+		case "discussions":
+			categories = append(categories, "social media")
+		case "academic":
+			categories = append(categories, "science")
+		case "news":
+			categories = append(categories, "news")
+		case "images":
+			categories = append(categories, "images")
+		case "videos":
+			categories = append(categories, "videos")
+		}
+	}
+
+	if len(categories) == 0 {
+		return []string{"general"}
+	}
+
+	return categories
+}