Remove unused fastapi/uvicorn deps and minor fixes

Fix README/code inconsistencies, remove unused BoundLLM

Render workflow diagram as PNG image instead of raw mermaid code

Use flash-lite for both models, remove demo subtitle

Remove model selector dropdown (Gemini-only deployment)

Fix: also patch _json_schema_to_python_type for boolean schema values

Fix: patch gradio_client.get_type to handle boolean JSON Schema values

Set Gemini Flash as default model

Fix: add type='messages' to gr.Chatbot for gradio 5.x compatibility

Fix: patch HfFolder for huggingface_hub 0.27+ compatibility

Fix: upgrade gradio to 5.x (HfFolder removed from huggingface_hub)

Initial commit: LangGraph multi-agent car finance chatbot