Add a CLI Example: “PLD in One Turn”

[kiyoshisasano]

📌 Summary

Create a simple command-line script that runs one assistant turn and prints the resulting PLD JSONL output.

🎯 Why

Helps new users understand PLD without LangGraph or larger infrastructure.

🛠 Scope

Script path: quickstart/run_cli_example.py

Use same initialization as existing examples

Print generated event to stdout