Ultra-robust monkey-patching and FER import safety

Fix FER import error and improve monkey-patching for Keras 3 compatibility

Update child level calculation and prepare for deployment

Fix: Monkey-patch tensorflow.keras and set Keras backend to torch to resolve FER import error on Hugging Face Spaces

Fix: Add keras to requirements to resolve FER import error on Hugging Face

Fix: Add automatic model reloading in backend and improve training feedback

fix: updated TemplateResponse signature for Starlette compatibility

fix: working version after HF changes

Update backend/requirements.txt

initial commit