修复子图中 state 的导入路径

backend/app/subgraphs/contact/graph.py

@@ -6,7 +6,7 @@ Contact Subgraph Builder
 
 from app.main_graph.graph import StateGraph, START, END
 
-from app.main_graph.state import ContactState
+from .state import ContactState
 from .nodes import create_contact_nodes
 
 

backend/app/subgraphs/contact/nodes.py

@@ -10,7 +10,7 @@ from datetime import datetime
 # 公共工具
 from ..common import MarkdownFormatter
 
-from app.main_graph.state import ContactState, ContactAction, Contact, Email
+from .state import ContactState
 from .api_client import ContactAPIClient
 
 

backend/app/subgraphs/dictionary/graph.py

@@ -5,7 +5,7 @@ Dictionary Subgraph Builder - Complete
 
 from app.main_graph.graph import StateGraph, START, END
 
-from app.main_graph.state import DictionaryState
+from .state import DictionaryState
 from .nodes import (
     parse_intent,
     query_word,

backend/app/subgraphs/dictionary/nodes.py

@@ -12,7 +12,7 @@ from ..common import (
     MarkdownFormatter
 )
 
-from app.main_graph.state import (
+from .state import (
     DictionaryState,
     DictionaryAction,
     WordEntry,

backend/app/subgraphs/news_analysis/graph.py

@@ -5,7 +5,7 @@ News Analysis Subgraph Builder
 
 from app.main_graph.graph import StateGraph, START, END
 
-from app.main_graph.state import NewsAnalysisState
+from .state import NewsAnalysisState
 from .nodes import (
     parse_intent,
     query_news,

backend/app/subgraphs/news_analysis/nodes.py

@@ -9,7 +9,7 @@ from datetime import datetime
 # 公共工具
 from ..common import MarkdownFormatter
 
-from app.main_graph.state import (
+from .state import (
     NewsAnalysisState,
     NewsAction,
     NewsItem,