리펙토링: 코드 최적화

app/(game)/play/PlayClient.tsx

@@ -38,13 +38,13 @@ export default function PlayClient({ problemCount }: PlayClientProps) {
   const [answerB, setAnswerB] = useState("");
   const [inputError, setInputError] = useState("");
 
+  const sessionProblemCount = session?.problems.length ?? null;
   const currentProblem = session?.problems[session.currentIndex] ?? null;
   const currentResult = session?.results[session.currentIndex] ?? null;
   const isComplete = Boolean(
     session && session.currentIndex >= session.problems.length,
   );
-  const sessionNeedsInit =
-    session === null || session.problems.length !== problemCount;
+  const sessionNeedsInit = sessionProblemCount !== problemCount;
   const correctCount =
     session?.results.filter((result) => result?.correct).length ?? 0;
   const totalCount = session?.problems.length ?? 0;
@@ -61,7 +61,7 @@ export default function PlayClient({ problemCount }: PlayClientProps) {
     initSession,
     problemCount,
     selectedProblemCount,
-    session,
+    sessionProblemCount,
     sessionNeedsInit,
     setProblemCount,
   ]);
@@ -89,7 +89,7 @@ export default function PlayClient({ problemCount }: PlayClientProps) {
     submitAnswer({ a: parsedA, b: parsedB });
   }
 
-  if (sessionNeedsInit) {
+  if (!session || sessionNeedsInit) {
     return (
       <main className="flex min-h-screen items-center bg-slate-50 px-6 py-12 text-slate-950">
         <section className="mx-auto w-full max-w-3xl">