Replace Azure Inference URL with GitHub Models API URL

## Issue Description This repository contains references to the old Azure inference URL that should be updated to use the new GitHub Models API endpoint. ### Current URL ``` https://models.inference.ai.azure.com ``` ### New URL ``` https://models.github.ai/inference ``` ## Why change is needed For GitHub Models API, the Azure inference endpoint is being deprecated: https://github.blog/changelog/2025-07-17-deprecation-of-azure-endpoint-for-github-models/ ## Action required * For all files that support GitHub Models, replace all instances of `https://models.inference.ai.azure.com` with `https://models.github.ai/inference` in the affected files. * If there is a model name that is being used with GitHub Models in the code, like "gpt-4o", change that model name to "openai/gpt-4o" instead - put "openai/" in front. For example, this new code would be correct when using GitHub Models with OpenAI: if API_HOST == "github": client = openai.OpenAI( base_url="https://models.github.ai/inference", api_key=os.environ["GITHUB_TOKEN"], ) MODEL_NAME = os.getenv("GITHUB_MODEL", "openai/gpt-4o") ## Details **Pattern:** `https://models.inference.ai.azure.com` ### Found matches in 2 file(s) with 3 total match(es): **File:** `src/backend/fastapi_app/openai_clients.py` - **Line 57:** `github_base_url = os.getenv("GITHUB_BASE_URL", "https://models.inference.ai.azure.com")` - **Line 117:** `github_base_url = os.getenv("GITHUB_BASE_URL", "https://models.inference.ai.azure.com")` **File:** `.env.sample` - **Line 40:** `GITHUB_BASE_URL=https://models.inference.ai.azure.com` **Repository:** https://github.com/Azure-Samples/rag-postgres-openai-python --- *This issue was automatically created by the GitHub Repo Maintainer Agent.*