feat(kiro): 新增 AWS Builder ID 授权码流程认证及用户邮箱获取增强

Amp-Thread-ID: https://ampcode.com/threads/T-019b2ecc-fb2d-713f-b30d-1196c7dce3e2
Co-authored-by: Amp <amp@ampcode.com>

internal/cmd/kiro_login.go

@@ -116,6 +116,54 @@ func DoKiroAWSLogin(cfg *config.Config, options *LoginOptions) {
 	fmt.Println("Kiro AWS authentication successful!")
 }
 
+// DoKiroAWSAuthCodeLogin triggers Kiro authentication with AWS Builder ID using authorization code flow.
+// This provides a better UX than device code flow as it uses automatic browser callback.
+//
+// Parameters:
+//   - cfg: The application configuration
+//   - options: Login options including prompts
+func DoKiroAWSAuthCodeLogin(cfg *config.Config, options *LoginOptions) {
+	if options == nil {
+		options = &LoginOptions{}
+	}
+
+	// Note: Kiro defaults to incognito mode for multi-account support.
+	// Users can override with --no-incognito if they want to use existing browser sessions.
+
+	manager := newAuthManager()
+
+	// Use KiroAuthenticator with AWS Builder ID login (authorization code flow)
+	authenticator := sdkAuth.NewKiroAuthenticator()
+	record, err := authenticator.LoginWithAuthCode(context.Background(), cfg, &sdkAuth.LoginOptions{
+		NoBrowser: options.NoBrowser,
+		Metadata:  map[string]string{},
+		Prompt:    options.Prompt,
+	})
+	if err != nil {
+		log.Errorf("Kiro AWS authentication (auth code) failed: %v", err)
+		fmt.Println("\nTroubleshooting:")
+		fmt.Println("1. Make sure you have an AWS Builder ID")
+		fmt.Println("2. Complete the authorization in the browser")
+		fmt.Println("3. If callback fails, try: --kiro-aws-login (device code flow)")
+		return
+	}
+
+	// Save the auth record
+	savedPath, err := manager.SaveAuth(record, cfg)
+	if err != nil {
+		log.Errorf("Failed to save auth: %v", err)
+		return
+	}
+
+	if savedPath != "" {
+		fmt.Printf("Authentication saved to %s\n", savedPath)
+	}
+	if record != nil && record.Label != "" {
+		fmt.Printf("Authenticated as %s\n", record.Label)
+	}
+	fmt.Println("Kiro AWS authentication successful!")
+}
+
 // DoKiroImport imports Kiro token from Kiro IDE's token file.
 // This is useful for users who have already logged in via Kiro IDE
 // and want to use the same credentials in CLI Proxy API.