Points: 3 days ddl@6.14 **Description:** Establish the foundational architecture for request handling in the serving layer. **Deliverables:** - Create a `serving_engine.py` module with common serving functionality: - Error response creation (standardized error formats) - Request field validation helpers - Common utilities for request preprocessing and postprocessing (if any) - Define protocol models for OpenAI-compatible API, copy `protocol.py` from the current `openai_api` directory. - Add utils.py with helper functions **Testing:** - Create test_serving_engine.py to test: - Error response formatting - Field validation logic - Proper handling of edge cases - Integration tests for the serving layer components