integration test fixes

src/services/db/user.db.ts

@@ -434,23 +434,21 @@ export class UserRepository {
    * @param refreshToken The refresh token to look up.
    * @returns A promise that resolves to the user object (id, email) or undefined if not found.
    */
-  // prettier-ignore
-  async findUserByRefreshToken(refreshToken: string, logger: Logger): Promise<{ user_id: string; email: string; }> {
+  async findUserByRefreshToken(
+    refreshToken: string,
+    logger: Logger,
+  ): Promise<{ user_id: string; email: string } | undefined> {
     try {
       const res = await this.db.query<{ user_id: string; email: string }>(
         'SELECT user_id, email FROM public.users WHERE refresh_token = $1',
-        [refreshToken]
+        [refreshToken],
       );
       if ((res.rowCount ?? 0) === 0) {
-        throw new NotFoundError('User not found for the given refresh token.');
+        return undefined;
       }
       return res.rows[0];
     } catch (error) {
-      if (error instanceof NotFoundError) throw error;
-      logger.error(
-        { err: error },
-        'Database error in findUserByRefreshToken',
-      );
+      logger.error({ err: error }, 'Database error in findUserByRefreshToken');
       throw new Error('Failed to find user by refresh token.'); // Generic error for other failures
     }
   }