v3.4: Fix build error - switch to tensorflow-cpu

Dockerfile

@@ -1,14 +1,17 @@
 FROM python:3.11-slim
 WORKDIR /app
 
-# Standard CV and HDF5 libraries
+# Essential system dependencies for TF-CPU, PIL, and OpenCV
 RUN apt-get update && apt-get install -y \
     libhdf5-dev \
     libgl1-mesa-glx \
     libglib2.0-0 \
+    libsm6 \
+    libxext6 \
     && rm -rf /var/lib/apt/lists/*
 
 COPY requirements.txt .
+RUN pip install --no-cache-dir --upgrade pip setuptools wheel
 RUN pip install --no-cache-dir -r requirements.txt
 
 COPY best_v6.keras .
@@ -17,5 +20,5 @@ COPY portal.html .
 COPY main.py .
 
 EXPOSE 7860
-# 1 worker to save RAM on free tier
+# Force single worker to avoid RAM spikes on Hugging Face free tier
 CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "7860", "--workers", "1"]

requirements.txt

@@ -1,7 +1,7 @@
 fastapi
 uvicorn[standard]
 python-multipart
-tensorflow==2.16.1
+tensorflow-cpu==2.16.1
 pillow
 numpy<2.0.0
 python-dotenv