PUT /users/{user_id}
====================

Summary
-------

Updates an existing user by ID.

Request
-------

**Method:** ``PUT``

**Path:** ``/users/{user_id}``

**Path Parameters:**

- ``user_id``: unique user ID

**Request Body:**

.. code-block:: json

   {
     "name": "Jeff Updated",
     "email": "jeff.updated@example.com"
   }

Response
--------

**200 OK**

.. code-block:: json

   {
     "id": "u_001",
     "name": "Jeff Updated",
     "email": "jeff.updated@example.com"
   }

**404 Not Found**

.. code-block:: json

   {
     "message": "User not found"
   }