Store calculation history on server with bazi input and chart snapshots.

Co-authored-by: Cursor <cursoragent@cursor.com>

Dockerfile

@@ -31,7 +31,9 @@ COPY --from=builder /app/public ./public
 # 卦辞 Markdown（运行时读取）
 COPY --from=builder /app/content ./content
 
-RUN mkdir -p public && chown -R nextjs:nodejs /app
+RUN mkdir -p /app/data/history \
+  && chown -R nextjs:nodejs /app/data \
+  && chown -R nextjs:nodejs /app
 
 USER nextjs
 EXPOSE 3130