Fix: use chromadb 0.4.24 for Python 3.14 compatibility

Fix: use Python 3.11 for chromadb compatibility

Force Python 3.11 for Render

Fix: remove pinned versions

Fix: pinned versions for faster build

Fix: clean requirements without conflicts

Fix: build index on startup, remove binary files

Initial deployment: RAG chatbot for microcenter.gr

initial commit

Duplicate from gradio-templates/chatbot