chore(dev): 按端口杀进程树，避免 Windows 孤儿监听

新增 stop.bat/ps1/sh，并写入本地开发规则：停服务用脚本、停后复核端口。

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

start.sh

@@ -74,7 +74,8 @@ echo "  数据库: localhost:5432"
 echo ""
 echo "  后端 PID: $BACKEND_PID"
 echo "  前端 PID: $FRONTEND_PID"
-echo "  停止服务: kill $BACKEND_PID $FRONTEND_PID && docker compose down"
+echo "  停止服务: ./stop.sh   （或 Ctrl+C 本脚本）"
+echo "  停库: docker compose down"
 echo "══════════════════════════════════════════"
 
 # 捕获 Ctrl+C，清理子进程