Two issues fixed:
1. Custom base URL wasn't being passed to the OpenAI client in
createProviderForModel() - requests went to api.openai.com instead
of the configured endpoint (e.g., LM Studio, llama.cpp)
2. Tool schemas were missing the "properties" field when tools had no
parameters. OpenAI API requires "properties" to always be present
as an object, even if empty.
Fixes#1154
rcourtman
900e05025a