infra: 무중단 배포 구성

- 엔드포인트에서 HTTP 200을 응답할 경우 서버 실행이 완료된 것으로 판단
- Blue/Green 배포 스크립트 작성(서버 내부)

Author: ysw789

src/main/java/dmu/dasom/api/global/healthcheck/HealthCheck.java

@@ -0,0 +1,15 @@
+package dmu.dasom.api.global.healthcheck;
+
+import io.swagger.v3.oas.annotations.tags.Tag;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@Tag(name = "health-check", description = "서버 상태 체크")
+public class HealthCheck {
+    @GetMapping("/api/health-check")
+    public ResponseEntity<Void> healthCheck() {
+        return ResponseEntity.ok().build();
+    }
+}