Simplify Dockerfile: split RUN commands for better error visibility

Dockerfile

@@ -21,12 +21,14 @@ RUN apt-get update && apt-get install -y \
 COPY requirements.txt .
 
 # Install Python dependencies
-# Install PyTorch CPU version first (requires special index)
-RUN pip install --no-cache-dir --upgrade pip setuptools wheel && \
-    pip install --no-cache-dir --extra-index-url https://download.pytorch.org/whl/cpu \
+# Upgrade pip first
+RUN pip install --no-cache-dir --upgrade pip setuptools wheel
+
+# Install PyTorch CPU version (requires special index)
+RUN pip install --no-cache-dir --extra-index-url https://download.pytorch.org/whl/cpu \
     torch==2.5.1+cpu torchvision==0.20.1+cpu
 
-# Install remaining dependencies
+# Install remaining dependencies from requirements.txt
 RUN pip install --no-cache-dir -r requirements.txt
 
 # Copy application files