Generative AI architecture — RAG patterns, LLM orchestration, multi-model tiering, agent workflow design, vector database architecture, knowledge connectors, and GenAI quality assurance. This skill should be used when the user asks to 'design RAG architecture', 'architect LLM system', 'select vector database', 'design AI agents', 'implement knowledge retrieval', 'plan GenAI quality', or mentions RAG, embeddings, vector search, LLM orchestration, agent framework, context-aware generation, hallucination reduction, or multi-model routing. [EXPLICIT]