修复子图中 state 的导入路径

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,