Update Dockerfile

Dockerfile

@@ -8,8 +8,8 @@ RUN apt-get update && apt-get install -y \
 
 ENV MPLCONFIGDIR=/tmp/matplotlib
 
-# Create static and heatmap directories
-RUN mkdir -p /app/static/heatmap
+# Create writable directory for heatmaps
+RUN mkdir -p /tmp/heatmaps
 
 COPY requirements.txt .
 RUN pip install --upgrade pip && \