This fixes GitHub issue #4122 where users following the documentation
examples using the 'embedder' key were getting OPENAI_API_KEY errors
when trying to use non-OpenAI embedding providers like Amazon Bedrock.
Changes:
- Add 'embedder' key to RagToolConfig TypedDict as alias for 'embedding_model'
- Normalize 'embedder' to 'embedding_model' in _validate_config method
- Add validation to reject configs with both keys specified
- Add tests for embedder key alias and Bedrock embedder configuration
Co-Authored-By: João <joao@crewai.com>