Description

Set a compliant User-Agent header on globaluserinfo API requests

The _get_user_info_request helper in TWLight/users/helpers/editor_data.py issued requests via urllib.request.urlopen() without setting a User-Agent header, so requests went out with Python's default Python-urllib/x.y agent. Wikimedia blocks this generic agent per its User Agent policy, returning HTTP 403 Forbidden.

Add a descriptive TWLIGHT_USER_AGENT constant containing the application name, URL, and contact address (sourced from TWLIGHT_ERROR_MAILTO), and send it via urllib.request.Request on the globaluserinfo query.

Phabricator Ticket

• https://phabricator.wikimedia.org/T431808

How Has This Been Tested?

• Verified against the live endpoint from the running container: the globaluserinfo call now returns 200 with real data ({'id': 69468694, 'name': 'TheresNoTime-WMF', 'editcount': 709}) instead of 403 Forbidden, and the full OAuth login / editor-creation path completes without the 500.
• Ran the existing users test suite (python manage.py test TWLight.users.tests)

Types of changes

What types of changes does your code introduce? Add an x in all the boxes that apply:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Minor change (fix a typo, add a translation tag, add section to README, etc.)