feat: local k3d dev env

[skl]

Local dev environment for kubernetes-mixin development and testing!

Run make dev to:

• Generate Grafana dashboard JSON files, Prometheus alert and recording rule files
• Create a local Kubernetes cluster using k3d
• Install Grafana, Prometheus, OTel Collector, kube-state-metrics, and node_exporter with helm

Output in your terminal:

╔═══════════════════════════════════════════════════════════════╗
║             🚀 Development Environment Ready! 🚀              ║
║                                                               ║
║   Run `make dev-port-forward`                                 ║
║   Grafana will be available at http://localhost:3000          ║
║                                                               ║
║   Data will be available in a few minutes.                    ║
║                                                               ║
║   Dashboards will refresh every 10s, run `make generate`      ║
║   and refresh your browser to see the changes.                ║
║                                                               ║
║   Alert and recording rules require `make dev-reload`.        ║
║                                                               ║
╚═══════════════════════════════════════════════════════════════╝

Rules are imported into the local Prometheus:

And visible in Grafana:

Here are the dashboards:

and an example showing data from its own cluster!