dockerfile edit

Dockerfile

@@ -10,10 +10,18 @@ ENV HOME=/home/user \
 
 WORKDIR /home/user/app
 
-# Install CPU-only PyTorch first (separate wheel index)
+# NOTE: this Dockerfile is NOT used by the deployed Space — README.md sets
+# `sdk: gradio`, so HF Spaces builds from requirements.txt on the managed
+# Gradio image and ignores this file entirely. It is kept only for local
+# Docker testing. ZeroGPU (spaces.GPU) is only supported on Gradio-SDK
+# Spaces, not Docker-SDK Spaces, so this file must never become the actual
+# build path if ZeroGPU is required.
+
+# Install PyTorch with CUDA support (default PyPI index) so torch.cuda is
+# available — ZeroGPU attaches a real GPU to the process at call time, so a
+# CPU-only wheel would make torch.cuda.is_available() return False.
 RUN pip install --no-cache-dir --user \
-    torch==2.4.0 torchvision==0.19.0 torchaudio==2.4.0 \
-    --index-url https://download.pytorch.org/whl/cpu
+    torch==2.4.0 torchvision==0.19.0 torchaudio==2.4.0
 
 # Install remaining dependencies
 COPY --chown=user requirements.txt .