fix: split pip install to avoid index-url conflict for non-torch packages

Dockerfile

@@ -5,9 +5,9 @@ RUN apt-get update && apt-get install -y \
     && rm -rf /var/lib/apt/lists/*
 
 RUN pip3 install --no-cache-dir \
-    flask flask-cors \
-    torch torchvision torchaudio --index-url https://download.pytorch.org/whl/cu121 \
-    numpy transformers accelerate sentencepiece protobuf
+    torch torchvision torchaudio --index-url https://download.pytorch.org/whl/cu121 && \
+    pip3 install --no-cache-dir \
+    flask flask-cors numpy transformers accelerate sentencepiece protobuf
 
 # Create non-root user (HF Spaces runs as uid 1000)
 RUN useradd -m -u 1000 user