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.

feat: Conditionally initialize database connection pool with error handling and raise an HTTP exception if not configured.

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