fix(governance): use real ASSERT schema and shared credentials

[placerda]

Summary

• update the governance skill and prompt-agent tutorial to scaffold the real assert-ai pipeline schema
• add shared Azure credential helpers for Doctor sources and runners
• harden ASSERT/Red Team runner behavior and related Doctor checks
• add unit coverage for shared credentials, runner outputs, and Doctor source handling

Validation

• python -m pytest tests/ -x -q
• python -m mypy src\agentops\agent\checks\opex.py src\agentops\agent\checks\regression.py src\agentops\agent\sources_credentials.py src\agentops\agent\sources\azure_monitor.py src\agentops\agent\sources\azure_resources.py src\agentops\agent\sources\foundry_control.py src\agentops\agent\sources\results_history.py src\agentops\cli\app.py src\agentops\services\assert_runner.py src\agentops\services\redteam_runner.py --ignore-missing-imports