style(dynamic-system-prompt-middleware): remove unused ModelResponse import

refactor(middleware): rename to reflect its purpose

feat(middleware): add dynamic prompt middleware example

feat(rag): add agent to orchestrate retrieval

feat(rag): add retriever tool wrapping the vector store retriever

refactor(rag): replace similarity search with retriever

feat: add RAG example with FAISS vector store

feat(deps): add faiss-cpu and langchain-community

style(multimodal-input): reorder kwargs and reformat list argument

style(agent-with-tools): rewrite comments for clarity and brevity

fix(multimodal-input): pass message list to invoke and print response

feat(multimodal-input): switch to base64-encoded local image input

feat(multimodal-input): add test image for base64 encoding example

refactor(multimodal-input): remove unused imports and system prompt

feat: add multimodal input example with OpenAI vision