Replace manual health endpoint with Spring Boot Actuator

Remove the hand-rolled HealthController and use spring-boot-starter-actuator
instead. Only the health endpoint is exposed, with no detail leakage.

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

backend/pom.xml

@@ -27,6 +27,11 @@
             <artifactId>spring-boot-starter-web</artifactId>
         </dependency>
 
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-actuator</artifactId>
+        </dependency>
+
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-test</artifactId>

backend/src/main/java/de/fete/adapter/in/web/HealthController.java

@@ -1,16 +0,0 @@
-package de.fete.adapter.in.web;
-
-import java.util.Map;
-import org.springframework.web.bind.annotation.GetMapping;
-import org.springframework.web.bind.annotation.RestController;
-
-/** REST endpoint for health checks. */
-@RestController
-public class HealthController {
-
-  /** Returns a simple health status. */
-  @GetMapping("/health")
-  public Map<String, String> health() {
-    return Map.of("status", "ok");
-  }
-}

backend/src/main/resources/application.properties

@@ -1 +1,4 @@
 spring.application.name=fete
+
+management.endpoints.web.exposure.include=health
+management.endpoint.health.show-details=never

backend/src/test/java/de/fete/FeteApplicationTest.java

@@ -24,8 +24,8 @@ class FeteApplicationTest {
 
   @Test
   void healthEndpointReturns200() throws Exception {
-    mockMvc.perform(get("/health"))
+    mockMvc.perform(get("/actuator/health"))
         .andExpect(status().isOk())
-        .andExpect(jsonPath("$.status").value("ok"));
+        .andExpect(jsonPath("$.status").value("UP"));
   }
 }