Error fixes

type mismatch in update user and some styling improvements

backend/src/handlers/auth.rs

@@ -268,7 +268,7 @@ pub async fn get_current_user(
 /// - `404 Not Found` if user doesn't exist
 /// - `500 Internal Server Error` if database error occurs
 pub async fn delete_user(
-    Path(id): Path<i32>,
+    Path(id): Path<i16>,
     State(data): State<Arc<AppState>>,
 ) -> Result<impl IntoResponse, (StatusCode, Json<serde_json::Value>)> {
     let query = sqlx::query(r#"DELETE FROM users WHERE id = $1"#)
@@ -411,7 +411,7 @@ pub async fn get_user_by_id(
 /// - This endpoint requires admin privileges (enforced by middleware via
 ///   [`validate_admin`](crate::cookie::validation::validate_admin)).
 pub async fn update_user(
-    Path(id): Path<i32>,
+    Path(id): Path<i16>,
     State(data): State<Arc<AppState>>,
     Json(body): Json<UserUpdateScheme>,
 ) -> Result<impl IntoResponse, (StatusCode, Json<serde_json::Value>)> {