feat(space): install CUDA-enabled PyTorch (cu121) for GPU on Space

Dockerfile

@@ -30,9 +30,9 @@ COPY . /app
 # Install deps
 RUN python -m pip install --upgrade pip && \
     python -m pip install -r requirements.txt && \
-    # CPU-only torch to avoid CUDA/xformers issues on Spaces CPU images
-    python -m pip install --index-url https://download.pytorch.org/whl/cpu torch torchvision torchaudio --upgrade --force-reinstall && \
-    # Ensure xformers is not installed
+    # Install CUDA-enabled PyTorch wheels (CUDA 12.1); required for GPU on Spaces
+    python -m pip install --index-url https://download.pytorch.org/whl/cu121 torch torchvision torchaudio --upgrade --force-reinstall && \
+    # Ensure xformers is not installed (optional perf lib; skip for compatibility)
     python -m pip uninstall -y xformers || true && \
     # Speed up and lower RAM during model load (avoid upgrading hub)
     python -m pip install --no-deps accelerate && \