Support simulating/testing identity & auth logic in local dev before deploying to AWS

[jesseturner21]

Summary

Customers want to simulate and test identity/auth logic in the local dev environment before deploying to AWS. Today, if an agent isn't deployed to AWS, the auth process can't be exercised locally — even when existing identity resources are available.

Problem

• Testing the auth/identity flow currently requires a full deployment to AWS.
• There's no way to validate identity logic locally against existing identity resources.
• This slows the dev loop: developers must deploy just to verify auth behaves as expected.

Desired behavior

• Ability to run/simulate the agent's identity and auth logic in the local dev environment.
• Local testing should be able to leverage existing identity resources so the auth process can be exercised without a deployment to AWS.

Environment

• CLI version: 0.22.0
• User agent: AgentCoreCLI/0.22.0 (darwin 25.5.0; node/v24.2.0)
• OS: darwin 25.5.0
• Node: v24.2.0