feat: 完善企业场景多线路由与执行稳定性

补齐平台模板与场景 DSL、预算控制、执行看板和企业场景脚本，增强 Windows 启动/迁移与前端代理和聊天会话记忆，修复执行创建阶段 500 与异步链路排障体验。

Made-with: Cursor

backend/app/core/error_handler.py

@@ -8,6 +8,7 @@ from fastapi.responses import JSONResponse
 from fastapi.exceptions import RequestValidationError
 from sqlalchemy.exc import SQLAlchemyError
 from app.core.exceptions import BaseAPIException
+from app.core.config import settings
 
 logger = logging.getLogger(__name__)
 
@@ -50,14 +51,28 @@ async def api_exception_handler(request: Request, exc: BaseAPIException):
 
 async def sqlalchemy_exception_handler(request: Request, exc: SQLAlchemyError):
     """处理数据库错误"""
-    logger.error(f"数据库错误: {str(exc)}", exc_info=True)
-    
+    orig = getattr(exc, "orig", None)
+    detail = str(orig) if orig is not None else str(exc)
+    logger.error(f"数据库错误: {detail}", exc_info=True)
+
+    user_msg = "数据库操作失败，请稍后重试"
+    # MySQL 1054 / 常见 DDL 滞后：模型已增列但库未 alembic upgrade
+    if "Unknown column" in detail or "(1054," in detail or "1054" in detail:
+        user_msg = (
+            "数据库表结构与当前代码不一致（常见为缺少 executions 新列等）。"
+            "请在 backend 目录执行：alembic upgrade head，然后重启 API 与 Celery。"
+        )
+
+    payload: dict = {
+        "error": "DATABASE_ERROR",
+        "message": user_msg,
+    }
+    if settings.DEBUG:
+        payload["detail"] = detail[:4000]
+
     return JSONResponse(
         status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
-        content={
-            "error": "DATABASE_ERROR",
-            "message": "数据库操作失败，请稍后重试"
-        }
+        content=payload,
     )
 
 
@@ -65,11 +80,15 @@ async def general_exception_handler(request: Request, exc: Exception):
     """处理通用异常"""
     logger.error(f"未处理的异常: {str(exc)}", exc_info=True)
     logger.error(f"异常堆栈: {traceback.format_exc()}")
-    
+
+    payload: dict = {
+        "error": "INTERNAL_ERROR",
+        "message": "服务器内部错误，请稍后重试",
+    }
+    if settings.DEBUG:
+        payload["detail"] = str(exc)[:4000]
+
     return JSONResponse(
         status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
-        content={
-            "error": "INTERNAL_ERROR",
-            "message": "服务器内部错误，请稍后重试"
-        }
+        content=payload,
     )