See parent epic for details

Acceptance Criteria:

• Docs should include the following:
  • How to setup principal/agent certs using pki commands (same as we have described upstream)
  • As per Slack thread, we are fine to use argocdagent cli to set this up, but  we MUST include the disclaimer saying that the pki commands are for non-production use cases. (https://redhat-internal.slack.com/archives/C01RQH8KQ87/p1759837449818769)
  • For production use cases, users should generate certificates on their own.
  • We don't need to document alternative pathways, for now.
  • BUT, I (Jonathan) will investigate how certmanager can be used for this so we have a suggestion for folks. (As per Slack thread)
• Docs should cover the following scenarios:
  • A) Setting up principal on OpenShift:
    • principal Argo CD agent installed via openshift gitops operator
    • principal Argo CD (used by Argo CD agent) installed via openshift gitops operator
    • We assume that principal is on an OpenShift cluster, and thus they can install/use OpenShift GitOps
  • B) Setting up agent on OpenShift (both managed and autonomous)
    • We will likewise assume that agent is ALSO is running on OpenShift, and will install Argo CD via OpenShift GitOps
    • Agent installed in B) will integrate with principal from A), above.
    • Argo CD agent installed via agent helm chart
      • Helm work is tracked on https://issues.redhat.com/browse/GITOPS-7749
    • Principal Argo CD installed via openshift gitops operator
    • Last I checked, in the install steps for this scenario we need to ask the user to create a NetworkPolicy which allows agent to connect to redis' Argo CD
  • As per Slack thread, we do NOT need to document anything related to OpenShift platform plus. (https://redhat-internal.slack.com/archives/C01RQH8KQ87/p1759952294702909)
  • Documentation for A) and B) will likely be very similar to https://github.com/argoproj-labs/argocd-agent/blob/main/docs/getting-started/openshift/index.md, BUT, that page is slightly old because it doesn't take into account changes we've made in argocd-operator.
  • C) Configuring an AppProject on principal, for agent
    • The URL linked above doesn't say how to create AppProject for the agent. We should mention how to do that.
    • This page contains that information, which we can steal from: https://argocd-agent.readthedocs.io/latest/user-guide/appprojects/
      • We don't need to include any of the transformation sections, best practices, etc.
      • Just providing AppProject examples for managed and autonomous agent is fine.
  • Produce doc draft, provide to Dhruv