feat: add keep-alive GitHub Action for Hugging Face Space and remove redundant startup model warm-up

feat: implement robust FaceNet weights download from Hugging Face to bypass unreliable DeepFace upstream sources

implement thread-safe FaceNet model initialization and pre-bake weights into Docker image

feat: Implement facial similarity checks for student registration and photo updates, and enhance frontend error handling and database connection resilience.

Implemented the first version of the application, handled the UI, face recognition, and database handling