updated dockerfile

Dockerfile

@@ -25,9 +25,10 @@ USER appuser
 ENV DEEPFACE_HOME=/app
 
 # Copy the requirements file from the 'model' directory
+# This step must happen after the user switch so pip installs for 'appuser'
 COPY model/requirements.txt .
 
-# Install Python dependencies
+# Install Python dependencies, including gunicorn
 RUN pip install --no-cache-dir -r requirements.txt
 
 # Copy the rest of the 'model' directory's contents