updated theming and fixed warnings

backend/src/error.rs

@@ -1,7 +1,7 @@
 use axum::{
+    Json,
     http::StatusCode,
     response::{IntoResponse, Response},
-    Json,
 };
 
 use crate::models::ErrorResponse;
@@ -38,4 +38,4 @@ where
     fn from(err: E) -> Self {
         AppError::Internal("Internal Server Error".to_string(), Some(err.to_string()))
     }
-}
+}