Update Dockerfile for CPU-only environment

Dockerfile

@@ -1,5 +1,5 @@
-# Use the official Ubuntu base image
-FROM ubuntu:22.04
+# Use a standard Python base image
+FROM python:3.9-slim
 
 # Set environment variables to non-interactive
 ENV DEBIAN_FRONTEND=noninteractive
@@ -28,6 +28,9 @@ ENV PATH="/home/user/venv/bin:$PATH"
 COPY --chown=user requirements.txt .
 RUN pip install --no-cache-dir -r requirements.txt
 
+# Add a comment about installing CPU-only dependencies here if needed for the full application
+# e.g., RUN pip install torch==1.x.x+cpu torchvision==0.x.x+cpu -f https://download.pytorch.org/whl/cpu/torch_stable.html
+
 # Copy application files
 COPY --chown=user app.py .