* fix(azure/chat/gpt_transformation.py): support api_version="preview"
Fixes https://github.com/BerriAI/litellm/issues/12945
* Fix anthropic passthrough logging handler model fallback for streaming requests (#13022)
* fix: anthropic passthrough logging handler model fallback for streaming requests
- Add fallback logic to retrieve model from logging_obj.model_call_details when request_body.model is empty
- Fixes issue #12933 where streaming requests to anthropic passthrough endpoints would crash due to missing model field
- Ensures downstream logging and cost calculation work correctly for all streaming scenarios
- Maintains backwards compatibility with existing non-streaming requests
* test: add minimal tests for anthropic passthrough logging handler model fallback
- Add unit tests for the model fallback logic in _handle_logging_anthropic_collected_chunks
- Test existing behavior when request_body.model is present
- Test fallback logic when request_body.model is empty but logging_obj.model_call_details has model
- Test edge cases where both sources are empty or missing
- Ensure backwards compatibility and graceful degradation
* fix(anthropic_passthrough_logging_handler.py): add provider to model name (accurate cost tracking)
* fix(anthropic_passthrough_logging_handler.py): don't reset custom llm provider, if already set
* fix: fix check
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Co-authored-by: Haggai Shachar <haggai.shachar@backline.ai>