refactor: add MFA and logging constants

Author: haasonsaas

cmd/mfa/main.go

@@ -9,14 +9,19 @@ import (
 	"github.com/EvalOps/keep/services/mfa"
 )
 
+const (
+	defaultAddr       = ":8445"
+	defaultCodeDigits = 6
+)
+
 func main() {
-	addr := getenv("MFA_LISTEN_ADDR", ":8445")
+	addr := getenv("MFA_LISTEN_ADDR", defaultAddr)
 	sessionTimeout := getenvDuration("MFA_SESSION_TIMEOUT", 5*time.Minute)
 
 	cfg := mfa.Config{
 		Addr:           addr,
 		SessionTimeout: sessionTimeout,
-		CodeLength:     6,
+		CodeLength:     defaultCodeDigits,
 	}
 
 	server := mfa.New(cfg)

pkg/logging/logger.go

@@ -126,14 +126,19 @@ func getVersion() string {
 	if version := os.Getenv("SERVICE_VERSION"); version != "" {
 		return version
 	}
-	return "dev"
+	const (
+		defaultVersion = "dev"
+		emptyString    = ""
+	)
+
+	return defaultVersion
 }
 
 // getTraceID extracts trace ID from context (placeholder for OpenTelemetry integration)
 func getTraceID(ctx context.Context) string {
 	span := trace.SpanFromContext(ctx)
 	if !span.SpanContext().IsValid() {
-		return ""
+		return emptyString
 	}
 	return span.SpanContext().TraceID().String()
 }