Names real technology throughout (Vault, Authentik, pfSense,
firewalld, Wazuh) instead of staying generic, adds a 'why this
approach vs the alternative' section to every doc, cross-links
heavily between docs instead of treating each system in isolation.
Mermaid diagrams up front, GFM alert callouts for key decisions and
gotchas, tables instead of bullet walls - replaces plain prose with
the visual template established for security-monitoring.md.
Secrets & PKI, Secret Distribution Model, SSO & Identity,
Firewall & Network Segmentation, DNS Naming Model, and Security
Monitoring - the first batch of per-system write-ups linked from
the new README, sourced and sanitized from the internal KB.