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/proxy/goproxy/goproxy.go

@@ -20,21 +20,21 @@ import (
 type Handler struct {
 	cache           *cache.Manager
 	client          *network.Client
-	upstream        string
-	sumDBURL        string
 	credExtractor   *auth.CredentialExtractor
 	credHasher      *auth.CredentialHasher
 	credValidator   *auth.GoValidator
 	validationCache *auth.ValidationCache
 	gitFetcher      *vcs.GitFetcher
 	moduleBuilder   *vcs.ModuleBuilder
+	upstream        string
+	sumDBURL        string
 }
 
 // Config holds Go proxy configuration
 type Config struct {
-	Upstream  string               // Upstream Go proxy (e.g., proxy.golang.org)
-	SumDBURL  string               // Checksum database URL
-	CredStore *vcs.CredentialStore // Optional credential store for git access
+	CredStore *vcs.CredentialStore
+	Upstream  string
+	SumDBURL  string
 }
 
 // New creates a new Go proxy handler