open-legal-products tightens Mike's credential boundaries

The maintainers have cleaned up how Mike handles its connection to its hosted data platform. If the backend is missing the address or privileged service credential it needs, it now stops with a clear error instead of proceeding with an unusable setup.

Just as importantly, the frontend setup guidance no longer suggests that a high-privilege service key should be supplied to the browser-facing application. That reduces the chance of teams exposing credentials that can bypass ordinary access controls while configuring a deployment.