Add Azure AI Foundry Claude Opus 4.5 Support

[dandinu]

Hi, have an Azure subscription that I wanted to test this on, so I did some minimal modifications to include it in the code (since you're already using the correct SDK, it was easy).

The PR, currently:

• adds support for Claude models via Azure AI Foundry (Microsoft Foundry)
• enables using azure_foundry/claude-opus-4-5 as a model option

Tests I've done

• verified client creation with Azure Foundry endpoint
• tested API call successfully returns Claude Opus 4.5 response
• Test integration with full BFTS pipeline

Configuration

  # Environment variables
  AZURE_FOUNDRY_ENDPOINT=https://<resource>.services.ai.azure.com/anthropic
  AZURE_FOUNDRY_API_KEY=<your-api-key>


  # bfts_config.yaml
  agent:
    code:
      model: azure_foundry/claude-opus-4-5