add Plano agent skills framework and rule set (#797)

* feat: add initial documentation for Plano Agent Skills

* feat: readme with examples

* feat: add detailed skills documentation and examples for Plano

---------

Co-authored-by: Adil Hafeez <adil.hafeez@gmail.com>

skills/plano-deployment-security/SKILL.md

@@ -0,0 +1,33 @@
+---
+name: plano-deployment-security
+description: Apply Plano deployment and production security practices. Use for Docker networking, state storage choices, readiness checks, and environment-based secret handling.
+license: Apache-2.0
+metadata:
+  author: katanemo
+  version: "1.0.0"
+---
+
+# Plano Deployment and Security
+
+Use this skill to harden production deployments and reduce runtime surprises.
+
+## When To Use
+
+- "Fix unreachable agents in Docker"
+- "Configure persistent conversation state"
+- "Add readiness and health checks"
+- "Prepare production deployment checklist"
+
+## Apply These Rules
+
+- `deploy-docker`
+- `deploy-state`
+- `deploy-health`
+
+## Execution Checklist
+
+1. Use `host.docker.internal` for host-side services from inside Plano container.
+2. Prefer PostgreSQL state storage for production multi-turn workloads.
+3. Verify `/healthz` before traffic or CI assertions.
+4. Ensure secrets remain environment-based, never hardcoded.
+5. Return deployment checks with failure-mode diagnostics.