geoffdavies-dt wires Mike up to Azure OpenAI

Out of the box, Mike talks to OpenAI's public service. Geoff Davies at Dovetail wanted to point it at Azure OpenAI - Microsoft's enterprise-hosted version of the same models, which a lot of regulated buyers prefer because data stays inside their Azure tenant and under their existing procurement and compliance paperwork.

The change is small but unlocks a lot: two configuration settings now let an operator redirect Mike to any OpenAI-compatible gateway and switch to Azure's authentication style. Default behaviour is unchanged, so existing deployments keep working. The trade-off Dovetail made to keep the patch tiny is that their Azure deployments have to be named to match Mike's expected model identifiers - they aligned the cloud to the code rather than the other way around.