Update Dockerfile

Dockerfile

@@ -27,6 +27,12 @@ RUN pip3 install --no-cache-dir -r backend/python/requirements.txt
 # Copy the rest of the application source code into the container.
 COPY . .
 
+# --- Create Runtime Directories & Set Permissions ---
+# Create directories that the application needs to write to at runtime.
+# Then, change their ownership to the non-root 'node' user so the app has write access.
+RUN mkdir -p /app/backend/uploads /app/backend/temp /app/backend/results /app/backend/database && \
+    chown -R node:node /app/backend/uploads /app/backend/temp /app/backend/results /app/backend/database
+
 # --- Build the React Frontend ---
 # This runs the memory-efficient build script from web/package.json
 # and creates the production build in /app/web/build