Document how to run Actors with restricted access (whitelabel access)

[drobnikj]

Why?

The Whitelabel access section
doesn't mention that an Actor run with a partner's API token gets full access to that partner's
Apify account by default. Partners running arbitrary Store Actors need to sandbox those runs with
a scoped token. We have a guide for it, but it's internal-only.

What?

Publish the internal guide in the public docs and link it from #### Whitelabel access:
Guide: How to execute Apify Actors with restricted access

Target section: sources/platform/integrations/integrate-with-apify.md, #### Whitelabel access
(under ### Pricing options).

How?

Up to the implementer — the guide is the source of truth for the content. Two notes:

• A separate page linked from #### Whitelabel access is probably better than expanding the
  section in place; the guide is long and also relevant outside the whitelabel context.
• The guide was last edited 2025-06-09 — verify the Console steps and screenshots against the
  current UI before publishing.