Function apply_compat_options 

pub fn apply_compat_options(
    p: OpenAiCompatibleModelProvider,
    opts: &ModelProviderRuntimeOptions,
) -> Box<dyn ModelProvider>

Apply cross-cutting compat post-processing (timeout, headers, api_path, max_tokens, reasoning effort) to a freshly-constructed compat provider and box it for trait-object dispatch. Single source of the post-process chain — every compat impl funnels through here.