Add debug listing to Dockerfile

Dockerfile

@@ -15,6 +15,7 @@ RUN pip install --no-cache-dir -r requirements.txt
 # Copy all necessary application files and folders from HFup/ to /app in the container
 # These paths are relative to the Dockerfile's location (i.e., inside HFup/)
 COPY app.py .
+RUN ls -la # Debug: List files in the build context root
 COPY bodybuilding_pose_analyzer bodybuilding_pose_analyzer
 COPY external external
 COPY yolov7 yolov7