claude: define skill for querying k8s OpenAPI via test cluster

Closes #265.

Author: jinnovation

.claude/skills/k8s-openapi/SKILL.md

@@ -0,0 +1,12 @@
+---
+name: k8s-openapi
+description: Reference the Kubernetes API. Useful for understanding what is possible via the Kubernetes REST API.
+---
+
+1. Start a test cluster with: `make test-cluster-create`. ONLY USE THIS SKILL ON THIS TEST CLUSTER.
+2. Use the new context only through `--context` and `--kubeconfig` on each `kubectl` command. Do not
+   alter the config via `kubectl config`.
+3. Start a proxy server with `kubectl proxy`
+4. Discover available endpoints by querying `/openapi/v3`
+5. Use the discovered endpoints to find out what you need to
+6. When you have found your answer, shut down the test cluster with `make test-cluster-stop`