feat(logging): introduce centralized logging with custom format and Gin integration

- Implemented a global logger with structured formatting for consistent log output.
- Added support for rotating log files using Lumberjack.
- Integrated new logging functionality with Gin HTTP server for unified log handling.
- Replaced direct `log.Info` calls with `fmt.Printf` in non-critical paths to simplify core functionality.

sdk/auth/claude.go

@@ -80,22 +80,22 @@ func (a *ClaudeAuthenticator) Login(ctx context.Context, cfg *config.Config, opt
 	state = returnedState
 
 	if !opts.NoBrowser {
-		log.Info("Opening browser for Claude authentication")
+		fmt.Println("Opening browser for Claude authentication")
 		if !browser.IsAvailable() {
 			log.Warn("No browser available; please open the URL manually")
 			util.PrintSSHTunnelInstructions(a.CallbackPort)
-			log.Infof("Visit the following URL to continue authentication:\n%s", authURL)
+			fmt.Printf("Visit the following URL to continue authentication:\n%s\n", authURL)
 		} else if err = browser.OpenURL(authURL); err != nil {
 			log.Warnf("Failed to open browser automatically: %v", err)
 			util.PrintSSHTunnelInstructions(a.CallbackPort)
-			log.Infof("Visit the following URL to continue authentication:\n%s", authURL)
+			fmt.Printf("Visit the following URL to continue authentication:\n%s\n", authURL)
 		}
 	} else {
 		util.PrintSSHTunnelInstructions(a.CallbackPort)
-		log.Infof("Visit the following URL to continue authentication:\n%s", authURL)
+		fmt.Printf("Visit the following URL to continue authentication:\n%s\n", authURL)
 	}
 
-	log.Info("Waiting for Claude authentication callback...")
+	fmt.Println("Waiting for Claude authentication callback...")
 
 	result, err := oauthServer.WaitForCallback(5 * time.Minute)
 	if err != nil {
@@ -131,9 +131,9 @@ func (a *ClaudeAuthenticator) Login(ctx context.Context, cfg *config.Config, opt
 		"email": tokenStorage.Email,
 	}
 
-	log.Info("Claude authentication successful")
+	fmt.Println("Claude authentication successful")
 	if authBundle.APIKey != "" {
-		log.Info("Claude API key obtained and stored")
+		fmt.Println("Claude API key obtained and stored")
 	}
 
 	return &TokenRecord{

sdk/auth/codex.go

@@ -79,22 +79,22 @@ func (a *CodexAuthenticator) Login(ctx context.Context, cfg *config.Config, opts
 	}
 
 	if !opts.NoBrowser {
-		log.Info("Opening browser for Codex authentication")
+		fmt.Println("Opening browser for Codex authentication")
 		if !browser.IsAvailable() {
 			log.Warn("No browser available; please open the URL manually")
 			util.PrintSSHTunnelInstructions(a.CallbackPort)
-			log.Infof("Visit the following URL to continue authentication:\n%s", authURL)
+			fmt.Printf("Visit the following URL to continue authentication:\n%s\n", authURL)
 		} else if err = browser.OpenURL(authURL); err != nil {
 			log.Warnf("Failed to open browser automatically: %v", err)
 			util.PrintSSHTunnelInstructions(a.CallbackPort)
-			log.Infof("Visit the following URL to continue authentication:\n%s", authURL)
+			fmt.Printf("Visit the following URL to continue authentication:\n%s\n", authURL)
 		}
 	} else {
 		util.PrintSSHTunnelInstructions(a.CallbackPort)
-		log.Infof("Visit the following URL to continue authentication:\n%s", authURL)
+		fmt.Printf("Visit the following URL to continue authentication:\n%s\n", authURL)
 	}
 
-	log.Info("Waiting for Codex authentication callback...")
+	fmt.Println("Waiting for Codex authentication callback...")
 
 	result, err := oauthServer.WaitForCallback(5 * time.Minute)
 	if err != nil {
@@ -130,9 +130,9 @@ func (a *CodexAuthenticator) Login(ctx context.Context, cfg *config.Config, opts
 		"email": tokenStorage.Email,
 	}
 
-	log.Info("Codex authentication successful")
+	fmt.Println("Codex authentication successful")
 	if authBundle.APIKey != "" {
-		log.Info("Codex API key obtained and stored")
+		fmt.Println("Codex API key obtained and stored")
 	}
 
 	return &TokenRecord{

sdk/auth/gemini.go

@@ -8,7 +8,6 @@ import (
 	"github.com/router-for-me/CLIProxyAPI/v6/internal/auth/gemini"
 	// legacy client removed
 	"github.com/router-for-me/CLIProxyAPI/v6/internal/config"
-	log "github.com/sirupsen/logrus"
 )
 
 // GeminiAuthenticator implements the login flow for Google Gemini CLI accounts.
@@ -57,7 +56,7 @@ func (a *GeminiAuthenticator) Login(ctx context.Context, cfg *config.Config, opt
 		"project_id": ts.ProjectID,
 	}
 
-	log.Info("Gemini authentication successful")
+	fmt.Println("Gemini authentication successful")
 
 	return &TokenRecord{
 		Provider: a.Provider(),

sdk/auth/qwen.go

@@ -51,19 +51,19 @@ func (a *QwenAuthenticator) Login(ctx context.Context, cfg *config.Config, opts
 	authURL := deviceFlow.VerificationURIComplete
 
 	if !opts.NoBrowser {
-		log.Info("Opening browser for Qwen authentication")
+		fmt.Println("Opening browser for Qwen authentication")
 		if !browser.IsAvailable() {
 			log.Warn("No browser available; please open the URL manually")
-			log.Infof("Visit the following URL to continue authentication:\n%s", authURL)
+			fmt.Printf("Visit the following URL to continue authentication:\n%s\n", authURL)
 		} else if err = browser.OpenURL(authURL); err != nil {
 			log.Warnf("Failed to open browser automatically: %v", err)
-			log.Infof("Visit the following URL to continue authentication:\n%s", authURL)
+			fmt.Printf("Visit the following URL to continue authentication:\n%s\n", authURL)
 		}
 	} else {
-		log.Infof("Visit the following URL to continue authentication:\n%s", authURL)
+		fmt.Printf("Visit the following URL to continue authentication:\n%s\n", authURL)
 	}
 
-	log.Info("Waiting for Qwen authentication...")
+	fmt.Println("Waiting for Qwen authentication...")
 
 	tokenData, err := authSvc.PollForToken(deviceFlow.DeviceCode, deviceFlow.CodeVerifier)
 	if err != nil {
@@ -101,7 +101,7 @@ func (a *QwenAuthenticator) Login(ctx context.Context, cfg *config.Config, opts
 		"email": tokenStorage.Email,
 	}
 
-	log.Info("Qwen authentication successful")
+	fmt.Println("Qwen authentication successful")
 
 	return &TokenRecord{
 		Provider: a.Provider(),