feat: add missing infrastructure kits

[Brad-Edwards]

Summary

Add eight reusable infrastructure kits covering certificate authority, DHCP/IPAM, secrets, messaging, caching, firewall/NAT, LDAP, and container orchestration. Each kit uses the existing RAES SDL and release layout, with benign seed inventory and default/variation compositions; the existing reverse-proxy kit covers load balancing.

Requirement UIDs

• (none — bug/refactor/maintenance run; see Traceability section below)

Related Issues

Closes #225

ADR Impact

• ADR-0021

Changes

• Publish eight 1.0.0 infrastructure kits with SDL modules, release metadata, seed and integration assets, composition fixtures, and associated-artifact manifests.
• Expand published-kit tests and the kit-author integration walkthrough to cover all 46 releases.
• Document the RAES boundary and kit design decisions in the implementation preflight note and integration runbook.

Test Plan

• Unit tests pass
• Integration tests pass if applicable
• Full completion suite required in CI before merge
• No coverage regression

Focused kit tests and the kit-author walkthrough pass. Repository unit tests, pack validation, release checks, and compileall are run locally.

Ground Control Checks

• Repository policy checks required in CI before merge
• Pre-push review completed; all findings fixed or dispositioned

Traceability

• IMPLEMENTS: feat(kits): add missing infrastructure kits #225 ← kits/infrastructure.*
• TESTS: feat(kits): add missing infrastructure kits #225 ← tests/test_published_kits.py, feat(kits): add missing infrastructure kits #225 ← tests_integration/kit_author_walkthrough.py

Checklist

• Code follows the project's coding standards
• Changelog: owned by Release Please (generated from the Conventional Commit PR title; no per-PR fragment)
• Architectural docs updated if stack, package structure, or key behaviors changed

Documentation

Updated: see diff.