fix(rectification): resolve typed focus answers deterministically

frontend/src/lib/rectification-agentic/core/build-state.ts

@@ -293,25 +293,21 @@ export function applyHoldoutAnswer(
   };
 }
 
-export function classifyChoiceAnswer(key: string, schema?: unknown): AnswerClass {
-  if (key === "A") return "yes";
-  if (key === "B") return "weak_yes";
-  if (key === "C") {
-    if (schemaMapsCToUnsure(schema)) return "unsure";
-    return "no";
-  }
-  return "unsure";
-}
-
-function schemaMapsCToUnsure(schema: unknown): boolean {
-  if (!schema || typeof schema !== "object") return false;
+export function classifyChoiceAnswer(key: string, schema?: unknown): AnswerClass | null {
+  if (!schema || typeof schema !== "object" || Array.isArray(schema)) return null;
   const row = schema as Record<string, unknown>;
-  if (row.choice_kind !== "varga_style") return false;
   const choice = row.choice && typeof row.choice === "object" && !Array.isArray(row.choice)
     ? row.choice as Record<string, unknown>
     : row;
-  const optionC = typeof choice.option_c === "string" ? choice.option_c : "";
-  return optionC.includes("都不像");
+  if (!Array.isArray(choice.options)) return null;
+  const option = choice.options.find((item) => (
+    item && typeof item === "object" && !Array.isArray(item) && (item as { key?: unknown }).key === key
+  ));
+  if (!option || typeof option !== "object") return null;
+  const answerClass = (option as { answer_class?: unknown }).answer_class;
+  return answerClass === "yes" || answerClass === "weak_yes" || answerClass === "no" || answerClass === "unsure"
+    ? answerClass
+    : null;
 }
 
 function rebuildWithAnswers(state: InferenceState, incoming: readonly ProbeAnswer[]): InferenceState {