feat: add robustness and testing stacks

[D2758695161]

Summary

This PR adds two new stacks to the homelab-stack repository:

1. Robustness Stack (stacks/robustness/) -- resolves #8 ($250 bounty)

• Cloudflare DDNS (hotio/cloudflare-ddns): Automatically updates a Cloudflare DNS A record when your public IP changes.
• Dnsmasq (ad-blocking DNS resolver): Local DNS with ad-blocking, with region-optimized upstream DNS (CN mode: Alibaba/Tencent DNS; INTL mode: Cloudflare/Google DNS).
• Network Test Runner (alpine): Hourly connectivity checks to CN and INTL endpoints.
• NAT Loopback documentation: Explains how to enable hairpin NAT on OpenWrt, pfSense, and generic routers.

2. Testing Stack (stacks/testing/) -- resolves #14 ($200 bounty)

• GitHub Actions Self-Hosted Runner (actions/runner:latest): Registers as a self-hosted runner with Docker-in-Docker support.
• Test Automation Container (docker:27-cli): Runs three validation scripts on startup:
  • validate-stacks.sh: Runs docker compose config --quiet on every stack
  • test-backup.sh: Full backup/restore cycle test
  • health-check.sh: Health status of all service containers across all stacks

How to Test

Robustness Stack

cd stacks/robustness
cp .env.example .env
# Edit .env with your Cloudflare credentials and REGION
docker compose up -d
docker compose logs -f

Testing Stack

cd stacks/testing
cp .env.example .env
# Edit .env with your GitHub PAT and repo URL
docker compose up -d

Files Changed

• stacks/robustness/docker-compose.yml
• stacks/robustness/.env.example
• stacks/robustness/README.md
• stacks/robustness/scripts/network-test.sh
• stacks/testing/docker-compose.yml
• stacks/testing/.env.example
• stacks/testing/README.md
• stacks/testing/scripts/validate-stacks.sh
• stacks/testing/scripts/test-backup.sh
• stacks/testing/scripts/health-check.sh

---

Bounties: #8 ($250 robustness) + #14 ($200 testing) = $450 total

[D2758695161]

@illbnm PR #395 adds robustness and testing stacks for your homelab. + bounty opportunity. Ready to merge!

[D2758695161]

?? Bump - this PR is ready to merge. Please let me know if you need any changes or have questions. Happy to iterate!