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/rules/deploy-state.md

@@ -0,0 +1,85 @@
+---
+title: Use PostgreSQL State Storage for Multi-Turn Conversations in Production
+impact: HIGH
+impactDescription: The default in-memory state storage loses all conversation history when the container restarts — production multi-turn agents require persistent PostgreSQL storage
+tags: deployment, state, postgres, memory, multi-turn, production
+---
+
+## Use PostgreSQL State Storage for Multi-Turn Conversations in Production
+
+`state_storage` enables Plano to maintain conversation context across requests. Without it, each request is stateless. The `memory` type works for development and testing — all state is lost on container restart. Use `postgres` for any production deployment where conversation continuity matters.
+
+**Incorrect (memory storage in production):**
+
+```yaml
+version: v0.3.0
+
+# Memory storage — all conversations lost on planoai down / container restart
+state_storage:
+  type: memory
+
+listeners:
+  - type: agent
+    name: customer_support
+    port: 8000
+    router: plano_orchestrator_v1
+    agents:
+      - id: support_agent
+        description: Customer support assistant with conversation history.
+```
+
+**Correct (PostgreSQL for production persistence):**
+
+```yaml
+version: v0.3.0
+
+state_storage:
+  type: postgres
+  connection_string: "postgresql://${DB_USER}:${DB_PASS}@${DB_HOST}:5432/${DB_NAME}"
+
+listeners:
+  - type: agent
+    name: customer_support
+    port: 8000
+    router: plano_orchestrator_v1
+    agents:
+      - id: support_agent
+        description: Customer support assistant with access to full conversation history.
+
+model_providers:
+  - model: openai/gpt-4o
+    access_key: $OPENAI_API_KEY
+    default: true
+```
+
+**Setting up PostgreSQL for local development:**
+
+```bash
+# Start PostgreSQL with Docker
+docker run -d \
+  --name plano-postgres \
+  -e POSTGRES_USER=plano \
+  -e POSTGRES_PASSWORD=devpassword \
+  -e POSTGRES_DB=plano \
+  -p 5432:5432 \
+  postgres:16
+
+# Set environment variables
+export DB_USER=plano
+export DB_PASS=devpassword
+export DB_HOST=host.docker.internal   # Use host.docker.internal from inside Plano container
+export DB_NAME=plano
+```
+
+**Production `.env` pattern:**
+
+```bash
+DB_USER=plano_prod
+DB_PASS=<strong-random-password>
+DB_HOST=your-rds-endpoint.amazonaws.com
+DB_NAME=plano
+```
+
+Plano automatically creates its state tables on first startup. The `connection_string` supports all standard PostgreSQL connection parameters including SSL: `postgresql://user:pass@host:5432/db?sslmode=require`.
+
+Reference: https://github.com/katanemo/archgw