add MoviePilot AI agent implementation and workflow manager

app/startup/agent_initializer.py

@@ -26,7 +26,7 @@ class AgentInitializer:
                 logger.info("AI智能体功能未启用")
                 return True
             
-            from app.agent.agent import agent_manager
+            from app.agent import agent_manager
             self.agent_manager = agent_manager
             
             await agent_manager.initialize()

app/startup/workflow_initializer.py

@@ -1,5 +1,4 @@
-from app.core.workflow import WorkFlowManager
-from app.chain.workflow import WorkflowChain
+from app.workflow import WorkFlowManager
 
 
 def init_workflow():