feat: add version info to health check endpoint

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend-node/src/app.ts

@@ -253,12 +253,15 @@ app.use("/api/", limiter);
 app.use("/api/", refreshTokenIfNeeded);
 
 // 헬스 체크 엔드포인트
+// eslint-disable-next-line @typescript-eslint/no-var-requires
+const { version } = require("../../package.json") as { version: string };
 app.get("/health", (req, res) => {
   res.status(200).json({
     status: "OK",
     timestamp: new Date().toISOString(),
     uptime: process.uptime(),
     environment: config.nodeEnv,
+    version,
   });
 });