Support overwriting model via environment

[rti]

Terms

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Description

We can set the model using the environment variable OLLAMA_MODEL_NAME already.
If we change the model string on docker run, the backend fails though, because the model was not pulled.

This ticket is about fixing this by pulling the model in start.sh too, not only in the Dockerfile.

This will also allow us to use small models by default on dev systems while using a different model in production.

Contribution

No response

[rti]

fixed in 69800b0

[rti]

part of #23