fix: use transactions when operations involve multiple database queries (#392)

Co-authored-by: Kyle Mendell <kmendell@ofkm.us>

backend/internal/utils/aaguid_util.go

@@ -12,9 +12,13 @@ import (
 
 var (
 	aaguidMap     map[string]string
-	aaguidMapOnce sync.Once
+	aaguidMapOnce *sync.Once
 )
 
+func init() {
+	aaguidMapOnce = &sync.Once{}
+}
+
 // FormatAAGUID converts an AAGUID byte slice to UUID string format
 func FormatAAGUID(aaguid []byte) string {
 	if len(aaguid) == 0 {