Verify ollama instructions across OSs

[juanfung]

The instructions in readme.md may not work for all operating systems. Need to verify and update.

On MacOS Tahoe 26.5, ollama version 0.30.6, this is what worked for me:

• If ollama client is running, stop it
• in your terminal:

$ launchctl setenv OLLAMA_HOST "0.0.0.0:11434"
$ ollama serve # if the client doesn't relaunch automatically

then run a model (if you run ollama serve in terminal, open a new terminal session:

$ ollama run gemma4:e4b"