Refactor code structure for improved readability and maintainability

backend/utils/drawingData.js

@@ -0,0 +1,12 @@
+export function normalizeStoredDrawingData(value) {
+    if (!value) return null;
+    let normalized = value;
+    for (let pass = 0; pass < 2 && typeof normalized === 'string'; pass += 1) {
+        try {
+            normalized = JSON.parse(normalized);
+        } catch (error) {
+            return value;
+        }
+    }
+    return typeof normalized === 'string' ? normalized : JSON.stringify(normalized);
+}