refactor(module_task): 移除节点分类相关代码

移除节点分类功能，包括前后端相关字段、枚举、表单和展示逻辑
优化任务调度器异常处理和日志记录
改进WebSocket聊天控制器的错误处理和连接关闭逻辑
增强节点调试功能，添加执行成功提示和跳转引导

backend/app/plugin/module_task/node/model.py

@@ -1,20 +1,9 @@
-import enum
-
 from sqlalchemy import Boolean, Integer, String, Text
 from sqlalchemy.orm import Mapped, mapped_column
 
 from app.core.base_model import ModelMixin, UserMixin
 
 
-class NodeCategoryEnum(enum.Enum):
-    """节点分类枚举"""
-
-    TRIGGER = "trigger"
-    ACTION = "action"
-    CONDITION = "condition"
-    CONTROL = "control"
-
-
 class NodeModel(ModelMixin, UserMixin):
     """
     节点类型模型 - 动态定义节点类型
@@ -26,7 +15,6 @@ class NodeModel(ModelMixin, UserMixin):
 
     name: Mapped[str] = mapped_column(String(64), nullable=False, comment="节点名称")
     code: Mapped[str] = mapped_column(String(32), nullable=False, unique=True, comment="节点编码")
-    category: Mapped[str] = mapped_column(String(32), default=NodeCategoryEnum.ACTION.value, comment="节点分类")
     jobstore: Mapped[str | None] = mapped_column(String(64), nullable=True, default="default", comment="存储器")
     executor: Mapped[str | None] = mapped_column(String(64), nullable=True, default="default", comment="执行器")
     trigger: Mapped[str | None] = mapped_column(String(64), nullable=True, comment="触发器")