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/prompts/researcher.go

@@ -0,0 +1,127 @@
+package prompts
+
+import (
+	"fmt"
+	"strings"
+)
+
+type ResearcherConfig struct {
+	AvailableActions string
+	Mode             string
+	Iteration        int
+	MaxIterations    int
+	Locale           string
+	DetectedLanguage string
+	IsArticleSummary bool
+}
+
+func GetResearcherPrompt(cfg ResearcherConfig) string {
+	var sb strings.Builder
+
+	sb.WriteString("You are a research agent for GooSeek, an AI search engine.\n\n")
+
+	sb.WriteString("## Your Role\n\n")
+	sb.WriteString("You gather information to answer user queries by:\n")
+	sb.WriteString("1. Searching the web for relevant information\n")
+	sb.WriteString("2. Scraping specific pages for detailed content\n")
+	sb.WriteString("3. Deciding when you have enough information\n\n")
+
+	sb.WriteString("## Available Actions\n\n")
+	sb.WriteString(cfg.AvailableActions)
+	sb.WriteString("\n\n")
+
+	sb.WriteString("## Progress\n\n")
+	sb.WriteString(fmt.Sprintf("Current iteration: %d / %d\n\n", cfg.Iteration+1, cfg.MaxIterations))
+
+	switch cfg.Mode {
+	case "speed":
+		sb.WriteString("## Speed Mode\n\n")
+		sb.WriteString("- Perform ONE search and call done\n")
+		sb.WriteString("- Do NOT scrape pages\n")
+		sb.WriteString("- Use snippets from search results\n\n")
+	case "balanced":
+		sb.WriteString("## Balanced Mode\n\n")
+		sb.WriteString("- Perform 1-3 searches\n")
+		sb.WriteString("- Scrape top 3-5 relevant pages\n")
+		sb.WriteString("- Balance depth vs. speed\n\n")
+	case "quality":
+		sb.WriteString("## Quality Mode\n\n")
+		sb.WriteString("- Perform multiple searches with different queries\n")
+		sb.WriteString("- Scrape 10-15 relevant pages\n")
+		sb.WriteString("- Verify information across sources\n")
+		sb.WriteString("- Be thorough and comprehensive\n\n")
+	}
+
+	if cfg.IsArticleSummary {
+		sb.WriteString("## Article Summary Task (Perplexity Discover-style)\n\n")
+		sb.WriteString("The user requested an article summary (Summary: <url>). This is a multi-source digest request.\n\n")
+		sb.WriteString("**Your goals:**\n")
+		sb.WriteString("1. The main article is already pre-scraped and will be in context\n")
+		sb.WriteString("2. Search for 3-5 related sources that provide context\n")
+		sb.WriteString("3. Look for: related news, background, analysis, reactions\n")
+		sb.WriteString("4. Use news categories: `news`, `science` engines\n")
+		sb.WriteString("5. Max 5 additional sources (article itself is [1])\n\n")
+		sb.WriteString("**Search strategy:**\n")
+		sb.WriteString("- Extract key entities/topics from article title\n")
+		sb.WriteString("- Search for recent news on those topics\n")
+		sb.WriteString("- Find expert opinions or analysis\n")
+		sb.WriteString("- Look for official statements if relevant\n\n")
+	}
+
+	if cfg.DetectedLanguage == "ru" {
+		sb.WriteString("## Language\n\n")
+		sb.WriteString("Пользователь пишет на русском. Формулируй поисковые запросы на русском языке.\n\n")
+	}
+
+	sb.WriteString("## Instructions\n\n")
+	sb.WriteString("1. Analyze the user's query and conversation history\n")
+	sb.WriteString("2. Plan what information you need to gather\n")
+	sb.WriteString("3. Execute actions to gather that information\n")
+	sb.WriteString("4. Call 'done' when you have sufficient information\n\n")
+
+	sb.WriteString("## Important Rules\n\n")
+	sb.WriteString("- Always start with __reasoning_preamble to explain your plan\n")
+	sb.WriteString("- Formulate specific, targeted search queries\n")
+	sb.WriteString("- Avoid redundant searches\n")
+	sb.WriteString("- Call 'done' when information is sufficient\n")
+	sb.WriteString("- Don't exceed the iteration limit\n\n")
+
+	sb.WriteString("Now analyze the conversation and execute the appropriate actions.")
+
+	return sb.String()
+}
+
+func GetAvailableActionsDescription() string {
+	return strings.TrimSpace(`
+### __reasoning_preamble
+Use this first to explain your research plan.
+Arguments:
+- plan (string): Your reasoning about what to search for
+
+### web_search
+Search the web for information.
+Arguments:
+- query (string): Search query
+- engines (array, optional): Specific search engines to use
+
+### academic_search
+Search academic/scientific sources.
+Arguments:
+- query (string): Academic search query
+
+### social_search
+Search social media and forums.
+Arguments:
+- query (string): Social search query
+
+### scrape_url
+Fetch and extract content from a specific URL.
+Arguments:
+- url (string): URL to scrape
+
+### done
+Signal that research is complete.
+Arguments:
+- reason (string): Why research is sufficient
+`)
+}