feat: 添加ComfyUI服务器持久化功能，支持服务器状态自动保存与恢复，增强系统的可靠性和可维护性

workflow_service/database/__init__.py

@@ -3,7 +3,7 @@
 提供工作流和工作流运行的数据库操作接口
 """
 
-from .models import Workflow, WorkflowRun, WorkflowRunNode
+from .models import Workflow, WorkflowRun, WorkflowRunNode, ComfyUIServer
 from .api import (
     init_db,
     save_workflow,
@@ -27,6 +27,7 @@ __all__ = [
     "Workflow",
     "WorkflowRun", 
     "WorkflowRunNode",
+    "ComfyUIServer",
     
     # API函数
     "init_db",

workflow_service/database/api.py

@@ -11,7 +11,7 @@ import uuid
 from sqlalchemy.future import select
 from sqlalchemy import delete
 
-from .models import Base, Workflow, WorkflowRun, WorkflowRunNode
+from .models import Base, Workflow, WorkflowRun, WorkflowRunNode, ComfyUIServer
 from .connection import async_engine, AsyncSessionLocal
 
 

workflow_service/database/models.py

@@ -4,7 +4,7 @@
 """
 
 from datetime import datetime
-from sqlalchemy import Column, String, Text, DateTime, ForeignKey
+from sqlalchemy import Column, String, Text, DateTime, ForeignKey, Integer, Boolean
 from sqlalchemy.ext.declarative import declarative_base
 from sqlalchemy.orm import relationship
 
@@ -109,3 +109,38 @@ class WorkflowRunNode(Base):
             "output_data": self.output_data,
             "error_message": self.error_message,
         }
+
+
+class ComfyUIServer(Base):
+    """ComfyUI 服务器模型"""
+
+    __tablename__ = "comfyui_servers"
+
+    name = Column(String, primary_key=True)
+    http_url = Column(String, nullable=False)
+    ws_url = Column(String, nullable=False)
+    status = Column(String, nullable=False, default="offline")
+    last_heartbeat = Column(DateTime)
+    last_health_check = Column(DateTime)
+    current_tasks = Column(Integer, default=0)
+    max_concurrent_tasks = Column(Integer, default=1)
+    capabilities = Column(Text)  # JSON 字符串
+    server_metadata = Column(Text)  # JSON 字符串
+    created_at = Column(DateTime, default=datetime.utcnow)
+    updated_at = Column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)
+
+    def to_dict(self) -> dict:
+        return {
+            "name": self.name,
+            "http_url": self.http_url,
+            "ws_url": self.ws_url,
+            "status": self.status,
+            "last_heartbeat": self.last_heartbeat.isoformat() if self.last_heartbeat else None,
+            "last_health_check": self.last_health_check.isoformat() if self.last_health_check else None,
+            "current_tasks": self.current_tasks,
+            "max_concurrent_tasks": self.max_concurrent_tasks,
+            "capabilities": self.capabilities,
+            "server_metadata": self.server_metadata,
+            "created_at": self.created_at.isoformat() if self.created_at else None,
+            "updated_at": self.updated_at.isoformat() if self.updated_at else None,
+        }