Initial infrastructure mono-repo scaffold

Consolidates nixos, docker, raspi, and debian-configuration into a single
infrastructure-as-code repo. Includes:

- ansible/: full inventory + proxmox-hardening, freeipa, and raspberrypi
  roles (converted from debian-configuration bash scripts)
- terraform/: Proxmox VMs, Dynu DNS, Pi-hole (decommissioned stub),
  Docker container catalog — migrated from docker/infrastructure/terraform/
- stacks/docker/, stacks/raspi/, nixos/: placeholder READMEs pending
  git subtree population (see implementation plan)
- docs/: internal MkDocs site with architecture, network topology, runbooks,
  and drift-detection guide; external sanitized site
- scripts/: drift-detect.sh, docs-build.sh, install-hooks.sh, check-secrets.sh
- CI: secret-scan (push/PR), drift-detect (daily), docs-build (on change)
- Pi-hole removed throughout — DNS is FreeIPA, DHCP is router

See docs/internal/implementation-plan.md for the phased rollout after
pushing to Gitea.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UvNjoxTWEDkhXsd1Dq2ETP

ansible/roles/freeipa/defaults/main.yml

@@ -0,0 +1,14 @@
+---
+# freeipa role defaults — all overridable in inventory host_vars or group_vars.
+# Most values come from the per-host inventory (see hosts.yml).
+
+ipa_realm: "SWEET.HOME"
+ipa_domain: "sweet.home"
+
+# Set these per-host in inventory/hosts.yml:
+# ipa_hostname: "domain-controller.sweet.home"
+# ipa_ip: "192.168.2.253"
+# ipa_dns_forwarder: "192.168.2.138"
+
+# Swap file created if no swap exists (FreeIPA needs headroom during install)
+ipa_swap_size_mb: 2048