chore: CI 용 헬스체크 API 추가

Author: Cupcakes33

.github/workflows/backend-deploy.yml

@@ -106,7 +106,7 @@ jobs:
 
             # 스모크 테스트
             sleep 5
-            curl -f http://localhost:8080/actuator/health || {
+            curl -f http://localhost:8080/internal/healthz || {
               echo "Health check failed. Rolling back..."
               mv -f /home/ec2-user/maru-backend.jar.bak /home/ec2-user/maru-backend.jar || true
               sudo systemctl restart maru-backend

backend/src/main/java/com/maru/config/SecurityConfig.java

@@ -54,7 +54,7 @@ public SecurityFilterChain securityFilterChain(HttpSecurity http) throws Excepti
                         "/api/v1/sms/**",
                         "/api/v1/dev/**",  // TODO: 테스트용. 프로덕션에서는 반드시 삭제할 것.
                         "/api/v1/dojangs/**", // TODO: 테스트용. 프로덕션에서는 반드시 삭제할 것.
-                        "/actuator/health",
+                        "/internal/healthz",
                         "/favicon.ico",
                         "/error"
                 ).permitAll()

backend/src/main/java/com/maru/controller/internal/HealthzController.java

@@ -0,0 +1,18 @@
+package com.maru.controller.internal;
+
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+public class HealthzController {
+
+    /**
+     * health 체크
+     *
+     * @return 응답
+     */
+    @GetMapping("/internal/healthz")
+    public String healthz() {
+        return "OK";
+    }
+}