Enhance RAG to agents lab workshop flow - #1

Summary

Updated rag_to_agents_lab.ipynb to make the lab more workshop-friendly while keeping the golden path runnable end-to-end.

Changes include:

• Added small workshop checkpoints for scenario selection, retrieval tuning, incident variation, tool behavior, unified query inputs, and memory scope comparison.
• Added the Developer Hub database telemetry identifier with oracledb.defaults.program.
• Integrated the latest OracleStore Decimal workaround from the updated notebook.
• Polished selected outputs with compact summaries, flow diagrams, and collapsed raw JSON where useful.
• Kept readiness output compact when all checks pass.

Validation

• Ran the notebook end-to-end.
• Confirmed error_outputs = 0.
• Confirmed no Traceback, KeyboardInterrupt, ORA-, or remember errors in the executed output.