feat: solution for 'Повторный экзамен #2: Граф с рефлексией на код'

src/state.py

@@ -1,10 +1,10 @@
-from typing import TypedDict, Dict
+from typing import TypedDict, Dict, Any
 
 class CodeReviewState(TypedDict):
     code: str
-    draft_review: str
-    criteria_scores: Dict[str, int]
-    weakest_criterion: str
-    verdict: str
+    draft_review: str | None
+    criteria_scores: Dict[str, int] | None
+    weakest_criterion: str | None
+    verdict: str | None  # "ok" | "needs_revision"
     round: int
     max_rounds: int