rglauco wires Mike for self-hosting

rglauco is rebuilding Mike so it can run without leaning on outside cloud services. The first move adds support for Ollama - a tool that runs AI models on your own machine instead of calling out to OpenAI or Anthropic - and rewires the app so users can pick it from the same model menu as the cloud options.

The second change is quieter but arguably bigger: documents no longer have to live in Supabase, the hosted backend Mike was built on. Files can now sit on the server's own disk, with short-lived links handling downloads. Together these changes carve out a path to running Mike entirely on infrastructure you control. A companion change for the database side is expected next.