Merge pull request #734 from AnguseZhang/refactor/state_key

feat: 添加StateKey类以支持未来的枚举扩展

Author: Rasic2

agents/matmaster_agent/state.py

@@ -1,3 +1,5 @@
+from enum import StrEnum
+
 # Special Key
 BIZ = 'biz'
 
@@ -13,3 +15,7 @@
 
 # Other Key
 STEP_DESCRIPTION = 'step_description'
+
+
+class StateKey(StrEnum):
+    pass