[WIP] Add Azure AI provider support

[Copilot]

Thanks for asking me to work on this. I will get started on it and keep this PR's description up to date as I form a plan and make progress.

Original description:

Add support for using Azure AI as a provider in nxtscape. Azure AI uses the OpenAI API but requires slightly different configuration values.

Requirements:

1. Add Azure AI as a new provider option
2. Support Azure-specific configuration parameters:
   • Azure OpenAI endpoint URL (different from standard OpenAI endpoint)
   • API version parameter (required for Azure OpenAI)
   • Deployment name (Azure-specific model deployment identifier)
   • API key authentication
3. Maintain compatibility with existing OpenAI provider functionality
4. Use the same OpenAI SDK/client but configure it for Azure endpoints
5. Add appropriate documentation and examples for Azure AI configuration
6. Include validation for Azure-specific required parameters

The implementation should allow users to configure Azure AI by specifying:

• Provider type as "azure" or similar
• Azure OpenAI resource endpoint
• API version (e.g., "2024-02-01")
• Deployment name instead of model name
• API key for authentication

This will enable users to leverage Azure OpenAI services while maintaining the same interface and functionality as the existing OpenAI provider.

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