feat: ✨ add config for log level

config.go

@@ -30,6 +30,7 @@ type Config struct {
 
 	ReconcileInterval time.Duration
 	DebounceDelay     time.Duration
+	LogLevel          string
 
 	RecordTTL         int
 	CloudflareAutoTTL bool
@@ -98,6 +99,13 @@ func LoadConfig() (*Config, error) {
 		return nil, fmt.Errorf("CF_AUTO_TTL: invalid boolean %q: %w", autoTTLStr, err)
 	}
 
+	cfg.LogLevel = strings.ToLower(envOrDefault("LOG_LEVEL", "info"))
+	switch cfg.LogLevel {
+	case "debug", "info", "warn", "error":
+	default:
+		return nil, fmt.Errorf("LOG_LEVEL: invalid value %q (allowed: debug, info, warn, error)", cfg.LogLevel)
+	}
+
 	cfg.ExcludeRouters = make(map[string]struct{})
 	if v := os.Getenv("EXCLUDE_ROUTERS"); v != "" {
 		for _, r := range strings.Split(v, ",") {