Fix OpenCV headless: pin version, remove GUI deps, fix matplotlib cache

Dockerfile

@@ -10,17 +10,15 @@ WORKDIR /app
 ENV PYTHONPATH="/app"
 ENV PYTHONDONTWRITEBYTECODE=1
 ENV PYTHONUNBUFFERED=1
-ENV MPLCONFIGDIR=/tmp/matplotlib
+ENV MPLCONFIGDIR=/app/matplotlib_cache
 ENV QT_QPA_PLATFORM=offscreen
+ENV OPENCV_IO_ENABLE_JASPER=0
+ENV OPENCV_IO_ENABLE_OPENEXR=0
 
 # Install minimal system dependencies for headless OpenCV
 RUN apt-get update && apt-get install -y \
     libglib2.0-0 \
-    libsm6 \
-    libxext6 \
-    libxrender1 \
     libgomp1 \
-    libglib2.0-0 \
     curl \
     && rm -rf /var/lib/apt/lists/*
 
@@ -39,7 +37,8 @@ COPY knowledge_base/ ./knowledge_base/
 COPY test_leaf_sample.jpg .
 
 # Create necessary directories
-RUN mkdir -p outputs temp /tmp/matplotlib
+RUN mkdir -p outputs temp /app/matplotlib_cache && \
+    chmod 777 /app/matplotlib_cache
 
 # Expose the port FastAPI runs on
 EXPOSE 7860

requirements.txt

@@ -11,7 +11,7 @@ uvicorn[standard]
 python-multipart
 # Image processing
 Pillow
-opencv-python-headless
+opencv-python-headless==4.8.1.78
 # Grad-CAM visualization
 grad-cam