fix: Docker 환경 health check package.json 경로 오류 수정

require("../../package.json")이 Docker 컨테이너(/app/src/)에서
모듈을 찾지 못해 서버가 크래시하는 문제를 try-catch로 해결한다.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend-node/src/app.ts

@@ -253,15 +253,26 @@ app.use("/api/", limiter);
 app.use("/api/", refreshTokenIfNeeded);
 
 // 헬스 체크 엔드포인트
-// eslint-disable-next-line @typescript-eslint/no-var-requires
+let appVersion = "unknown";
-const { version } = require("../../package.json") as { version: string };
+try {
+  // 로컬: ../../package.json, Docker(/app/src/): ../package.json
+  // eslint-disable-next-line @typescript-eslint/no-var-requires
+  appVersion = require("../../package.json").version;
+} catch {
+  try {
+    // eslint-disable-next-line @typescript-eslint/no-var-requires
+    appVersion = require("../package.json").version;
+  } catch {
+    /* version stays "unknown" */
+  }
+}
 app.get("/health", (req, res) => {
   res.status(200).json({
     status: "OK",
     timestamp: new Date().toISOString(),
     uptime: process.uptime(),
     environment: config.nodeEnv,
-    version,
+    version: appVersion,
   });
 });