Enable GPU support via CUDA base image

Dockerfile

@@ -1,13 +1,16 @@
 # ───────────────────────────────────────────────────────────
 # Word-As-Image  •  FastAPI GPU Space  •  builds diffvg
 # ───────────────────────────────────────────────────────────
-FROM python:3.10-slim
+FROM nvidia/cuda:11.8.0-cudnn8-devel-ubuntu22.04
 
 # —— OS packages needed by diffvg & image libs ———————————
 RUN apt-get update && apt-get install -y --no-install-recommends \
+        python3 python3-pip python3-venv \
         build-essential git cmake ffmpeg pkg-config \
         libgl1-mesa-dev libglib2.0-0 libpng-dev libxrender1 xorg-dev \
-    && rm -rf /var/lib/apt/lists/*
+    && rm -rf /var/lib/apt/lists/* \
+    && ln -s /usr/bin/python3 /usr/local/bin/python \
+    && ln -s /usr/bin/pip3 /usr/local/bin/pip
 
 # —— Non-root user per HF best practice ————————————————
 RUN useradd -m -u 1000 appuser
@@ -25,6 +28,8 @@ ENV HF_HOME=/home/appuser/.cache/huggingface \
 # —— Python deps (NO diffvg here) ————————————————
 COPY --chown=appuser requirements.txt .
 RUN pip install --upgrade pip \
+ && pip install --no-cache-dir torch==2.3.1+cu118 torchvision==0.18.1+cu118 \
+    --extra-index-url https://download.pytorch.org/whl/cu118 \
  && pip install --no-cache-dir -r requirements.txt
 
 # —— Build diffvg from a known-good commit ——————————

requirements.txt

@@ -1,6 +1,6 @@
-torch==2.3.1
-torchvision==0.18.1
 xformers==0.0.27
+torch==2.3.1+cu118
+torchvision==0.18.1+cu118
 
 accelerate==1.0.1
 annotated-types==0.7.0