refactor: reorganize struct fields, add new handlers and storage backends

- [x] Reorder struct fields across codebase for consistency
- [x] Add analytics event handlers and tests
- [x] Add authentication API key management handlers and tests
- [x] Add pre-warming control handlers and tests
- [x] Implement S3 storage backend with tests
- [x] Implement SMB/CIFS storage backend with tests
- [x] Add CDN middleware tests
- [x] Integrate analytics tracking into cache manager
- [x] Add S3 and SMB storage initialization in app setup
- [x] Add CDN caching to proxy handlers
- [x] Remove distributed locking (Redis lock manager)
- [x] Remove proxy common package and utilities
- [x] Remove standalone HTTP server package
- [x] Remove logger middleware
- [x] Simplify error handling utilities
- [x] Update config with S3 and SMB options
- [x] Update cache manager signature to include analytics

pkg/app/handlers_analytics.go

@@ -0,0 +1,149 @@
+package app
+
+import (
+	"strconv"
+
+	"github.com/gofiber/fiber/v2"
+	"github.com/rs/zerolog/log"
+)
+
+// handleAnalyticsTopPackages returns the most downloaded packages
+func (a *App) handleAnalyticsTopPackages(c *fiber.Ctx) error {
+	c.Set("Content-Type", "application/json")
+	c.Set("Access-Control-Allow-Origin", "*")
+
+	// Get limit from query params (default: 10)
+	limit := 10
+	if limitStr := c.Query("limit"); limitStr != "" {
+		if parsedLimit, err := strconv.Atoi(limitStr); err == nil && parsedLimit > 0 {
+			limit = parsedLimit
+		}
+	}
+
+	packages := a.analyticsEngine.GetTopPackages(limit)
+
+	return c.Status(fiber.StatusOK).JSON(fiber.Map{
+		"packages": packages,
+		"total":    len(packages),
+	})
+}
+
+// handleAnalyticsTrendingPackages returns trending packages
+func (a *App) handleAnalyticsTrendingPackages(c *fiber.Ctx) error {
+	c.Set("Content-Type", "application/json")
+	c.Set("Access-Control-Allow-Origin", "*")
+
+	// Get limit from query params (default: 10)
+	limit := 10
+	if limitStr := c.Query("limit"); limitStr != "" {
+		if parsedLimit, err := strconv.Atoi(limitStr); err == nil && parsedLimit > 0 {
+			limit = parsedLimit
+		}
+	}
+
+	packages := a.analyticsEngine.GetTrendingPackages(limit)
+
+	return c.Status(fiber.StatusOK).JSON(fiber.Map{
+		"packages": packages,
+		"total":    len(packages),
+	})
+}
+
+// handleAnalyticsTrends returns download trends over time
+func (a *App) handleAnalyticsTrends(c *fiber.Ctx) error {
+	c.Set("Content-Type", "application/json")
+	c.Set("Access-Control-Allow-Origin", "*")
+
+	trends := a.analyticsEngine.GetTrends()
+
+	return c.Status(fiber.StatusOK).JSON(fiber.Map{
+		"trends": trends,
+	})
+}
+
+// handleAnalyticsTotalStats returns overall statistics
+func (a *App) handleAnalyticsTotalStats(c *fiber.Ctx) error {
+	c.Set("Content-Type", "application/json")
+	c.Set("Access-Control-Allow-Origin", "*")
+
+	stats := a.analyticsEngine.GetTotalStats()
+
+	return c.Status(fiber.StatusOK).JSON(stats)
+}
+
+// handleAnalyticsRegistryStats returns per-registry statistics
+func (a *App) handleAnalyticsRegistryStats(c *fiber.Ctx) error {
+	c.Set("Content-Type", "application/json")
+	c.Set("Access-Control-Allow-Origin", "*")
+
+	registry := c.Params("registry")
+	if registry == "" {
+		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
+			"error": "registry parameter is required",
+		})
+	}
+
+	stats := a.analyticsEngine.GetRegistryStats(registry)
+
+	return c.Status(fiber.StatusOK).JSON(stats)
+}
+
+// handleAnalyticsPackageStats returns statistics for a specific package
+func (a *App) handleAnalyticsPackageStats(c *fiber.Ctx) error {
+	c.Set("Content-Type", "application/json")
+	c.Set("Access-Control-Allow-Origin", "*")
+
+	registry := c.Params("registry")
+	name := c.Params("name")
+
+	if registry == "" || name == "" {
+		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
+			"error": "registry and name parameters are required",
+		})
+	}
+
+	stats, exists := a.analyticsEngine.GetPackageStats(registry, name)
+	if !exists {
+		return c.Status(fiber.StatusNotFound).JSON(fiber.Map{
+			"error": "package not found in analytics",
+		})
+	}
+
+	return c.Status(fiber.StatusOK).JSON(fiber.Map{
+		"package": stats,
+	})
+}
+
+// handleAnalyticsSearch searches for packages matching a query
+func (a *App) handleAnalyticsSearch(c *fiber.Ctx) error {
+	c.Set("Content-Type", "application/json")
+	c.Set("Access-Control-Allow-Origin", "*")
+
+	query := c.Query("q")
+	if query == "" {
+		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
+			"error": "query parameter 'q' is required",
+		})
+	}
+
+	// Get limit from query params (default: 20)
+	limit := 20
+	if limitStr := c.Query("limit"); limitStr != "" {
+		if parsedLimit, err := strconv.Atoi(limitStr); err == nil && parsedLimit > 0 {
+			limit = parsedLimit
+		}
+	}
+
+	results := a.analyticsEngine.SearchPackages(query, limit)
+
+	log.Debug().
+		Str("query", query).
+		Int("results", len(results)).
+		Msg("Analytics search completed")
+
+	return c.Status(fiber.StatusOK).JSON(fiber.Map{
+		"results": results,
+		"total":   len(results),
+		"query":   query,
+	})
+}