Understanding-oriented content explaining the "why" behind BlumeOps:
- why-gitops: Philosophy of infrastructure-as-code for homelabs
- architecture: How all the pieces fit together (hosts, services, data flow)
- security-model: Tailscale networking, 1Password secrets, access control
Also updates docs/index.md with How-to and Explanation sections.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>