Requests API: `timeline_focused` returns 500 when using link from request response

[Samk13]

Package version (if known): 14.0.0b10.dev5
file_storage: S3

Describe the bug

Calling the timeline_focused endpoint via the link returned in the request payload results in a 500 error.
e.g: https://127.0.0.1:5000/api/requests/<UUID>/timeline_focused

Steps to Reproduce

1. Fetch a request: GET /api/requests/<id>
2. From the response, follow: links.timeline_focused

Expected behavior

Not getting a 500

Screenshots (if applicable)

"GET /api/requests/4f523918-f74c-4935-b558-e81875dc3329/timeline_focused HTTP/1.1" 500 -
Traceback (most recent call last):
  File "/Users/test-user/invenio-dev-latest/.venv/lib/python3.14/site-packages/flask/app.py", line 1536, in __call__
    return self.wsgi_app(environ, start_response)
           ~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/test-user/invenio-dev-latest/.venv/lib/python3.14/site-packages/werkzeug/middleware/dispatcher.py", line 81, in __call__
    return app(environ, start_response)
  File "/Users/test-user/invenio-dev-latest/.venv/lib/python3.14/site-packages/flask/app.py", line 1536, in __call__
    return self.wsgi_app(environ, start_response)
           ~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/test-user/invenio-dev-latest/.venv/lib/python3.14/site-packages/flask/app.py", line 1514, in wsgi_app
    response = self.handle_exception(e)
  File "/Users/test-user/invenio-dev-latest/.venv/lib/python3.14/site-packages/flask/app.py", line 1511, in wsgi_app
    response = self.full_dispatch_request()
  File "/Users/test-user/invenio-dev-latest/.venv/lib/python3.14/site-packages/flask/app.py", line 919, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/Users/test-user/invenio-dev-latest/.venv/lib/python3.14/site-packages/flask/app.py", line 917, in full_dispatch_request
    rv = self.dispatch_request()
  File "/Users/test-user/invenio-dev-latest/.venv/lib/python3.14/site-packages/flask/app.py", line 902, in dispatch_request
    return self.ensure_sync(self.view_functions[rule.endpoint])(**view_args)  # type: ignore[no-any-return]
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^
  File "/Users/test-user/invenio-dev-latest/.venv/lib/python3.14/site-packages/flask_resources/resources.py", line 65, in view
    return view_meth()
  File "/Users/test-user/invenio-dev-latest/.venv/lib/python3.14/site-packages/flask_resources/content_negotiation.py", line 116, in inner_content_negotiation
    return f(*args, **kwargs)
  File "/Users/test-user/invenio-dev-latest/.venv/lib/python3.14/site-packages/flask_resources/parsers/decorators.py", line 51, in inner
    return f(self, *args, **kwargs)
  File "/Users/test-user/invenio-dev-latest/.venv/lib/python3.14/site-packages/flask_resources/parsers/decorators.py", line 51, in inner
    return f(self, *args, **kwargs)
  File "/Users/test-user/invenio-dev-latest/.venv/lib/python3.14/site-packages/flask_resources/parsers/decorators.py", line 51, in inner
    return f(self, *args, **kwargs)
  File "/Users/test-user/invenio-dev-latest/.venv/lib/python3.14/site-packages/flask_resources/responses.py", line 39, in inner
    res = f(*args, **kwargs)
  File "/Users/test-user/invenio-dev-latest/.venv/lib/python3.14/site-packages/invenio_requests/resources/events/resource.py", line 172, in focused_list
    hits = self.service.focused_list(

  File "/Users/test-user/invenio-dev-latest/.venv/lib/python3.14/site-packages/invenio_requests/services/events/service.py", line 451, in focused_list
    search = self._search(

  File "/Users/test-user/invenio-dev-latest/.venv/lib/python3.14/site-packages/invenio_records_resources/services/records/service.py", line 220, in _search
    search = self.search_request(

  File "/Users/test-user/invenio-dev-latest/.venv/lib/python3.14/site-packages/invenio_records_resources/services/records/service.py", line 194, in search_request
    search = interpreter_cls(search_opts).apply(identity, search, params)
  File "/Users/test-user/invenio-dev-latest/.venv/lib/python3.14/site-packages/invenio_records_resources/services/records/params/pagination.py", line 38, in apply
    if not p.valid():
           ~~~~~~~^^
  File "/Users/test-user/invenio-dev-latest/.venv/lib/python3.14/site-packages/invenio_records_resources/pagination.py", line 31, in valid
    pre_condition = 1 <= self.size and 1 <= self.page
                    ^^^^^^^^^^^^^^
TypeError: '<=' not supported between instances of 'int' and 'NoneType'