Replaces the placeholder "Success Metrics" section with a detailed walkthrough of the internal PKI: Step CA provisioners, cert-manager + StepClusterIssuer wiring, certificate issuance/renewal sequence diagram, device-trust installation steps, and troubleshooting playbook for the common stuck-CertificateRequest / Traefik TLS / device-trust failures. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>