feat(auth): enhance authentication system with multi-user support and admin role management

- Implemented multi-user authentication with role-based access control.
- Added environment variables for initial admin user setup.
- Updated README and example environment file with new authentication options.
- Introduced user and system configuration models in the database schema.
- Enhanced authentication middleware to support user registration and role management.
- Updated frontend to handle new authentication flows, including admin user creation and role updates.

frontend/src/utils/importUtils.ts

@@ -75,17 +75,12 @@ export const importDrawings = async (
           headers: {
             // Backend uses this header to apply stricter validation for imported files.
             "X-Imported-File": "true",
-          },
-          onUploadProgress: (progressEvent) => {
-            if (onProgress && progressEvent.total) {
-              const percentCompleted = Math.round(
-                (progressEvent.loaded * 100) / progressEvent.total
-              );
-              onProgress(fileIndex, 'uploading', percentCompleted);
-            }
+            "Content-Type": "application/json",
           },
         });
 
+        if (onProgress) onProgress(fileIndex, 'uploading', 100);
+
         if (onProgress) onProgress(fileIndex, 'success', 100);
         successCount++;