feat: create standalone native fnOS repository

app-src/internal/ddns/dnsutil.go

@@ -0,0 +1,25 @@
+package ddns
+
+import "strings"
+
+func fqdnForRecord(rootDomain, recordName string) string {
+	recordName = strings.TrimSpace(recordName)
+	if recordName == "" || recordName == "@" {
+		return rootDomain
+	}
+	if strings.Contains(recordName, ".") {
+		return recordName
+	}
+	if recordName == "*" {
+		return "*." + rootDomain
+	}
+	return recordName + "." + rootDomain
+}
+
+func subDomainForRecord(recordName string) string {
+	recordName = strings.TrimSpace(recordName)
+	if recordName == "" || recordName == "@" {
+		return "@"
+	}
+	return recordName
+}