Pattern for governing Copilot Studio agents before they reach production

For me the sponsor should accept a small, versioned mandate before the agent is shared: business purpose, allowed actions, data boundary, expiry date and who can suspend it. I would keep the business sponsor, technical owner and data owner explicit, even when one person covers more than one role.
This is the approach I document in my published PALO Framework (https://paloframework.org/PALO_AIGovernance.html), with PALO-AM for delegated authority and the lifecycle gates Frame, Classify, Assess, Control, Measure, Prove & Review. Applied to your example, the release record should bind the sponsor decision to the actual agent version and knowledge sources. A change of tool, data source or audience should trigger a review of the affected controls. I would also test the handover case: the sponsor leaves, an escalation is raised and someone has authority to stop or renew the agent. A name in the registry alone does not prove that this works.
For the first pilot, I would measure agents without an accountable owner, overdue reviews and unresolved exceptions, with an owner and response deadline for each. PALO provides the documented governance model; production readiness still needs evidence from the specific Copilot deployment.