Re-check multilevel fallback validation test suite for OnCall.ai

feat(user_prompt): Enhance Medical Query Processing Pipeline

feat(user_prompt): update UserPromptProcessor to integrate Llama3-Med42-70B and enhance query validation; add unit tests for condition extraction and matching mechanisms

feat(user_prompt): add keyword index checking and enhance medical query validation (add validate_medical_query() and _check_keyword_in_index(), based on implementation_todo_20250730_user_prompt.md

🚀 Implement Advanced Condition Extraction for Medical Query Processing