feat(request-delay): 新增可配置的请求延迟功能，支持在 application.yml 中启用和设置延迟时长

src/main/java/work/baiyun/chronicdiseaseapp/aspect/RequestDelayAspect.java

@@ -0,0 +1,49 @@
+package work.baiyun.chronicdiseaseapp.aspect;
+
+import org.aspectj.lang.ProceedingJoinPoint;
+import org.aspectj.lang.annotation.Around;
+import org.aspectj.lang.annotation.Aspect;
+import org.aspectj.lang.annotation.Pointcut;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Component;
+
+/**
+ * 开发/测试用：为 Controller 层请求注入可配置的延迟（默认关闭）。
+ * 通过设置 application.properties 中的 `app.simulatedDelay.enabled=true` 来启用，
+ * 延迟时长可通过 `app.simulatedDelay.millis` 配置（毫秒）。
+ */
+@Aspect
+@Component
+public class RequestDelayAspect {
+
+    private static final Logger logger = LoggerFactory.getLogger(RequestDelayAspect.class);
+
+    @Value("${app.simulatedDelay.enabled:false}")
+    private boolean enabled;
+
+    @Value("${app.simulatedDelay.millis:1000}")
+    private long delayMillis;
+
+    // 切点：拦截所有 controller 包下的方法
+    @Pointcut("execution(* work.baiyun.chronicdiseaseapp.controller..*(..))")
+    public void controllerMethods() {}
+
+    @Around("controllerMethods()")
+    public Object aroundController(ProceedingJoinPoint pjp) throws Throwable {
+        if (!enabled) {
+            return pjp.proceed();
+        }
+
+        try {
+            Thread.sleep(delayMillis);
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+            logger.warn("Simulated delay interrupted", e);
+        }
+
+        logger.debug("Applied simulated delay {} ms to {}", delayMillis, pjp.getSignature().toShortString());
+        return pjp.proceed();
+    }
+}

src/main/resources/application.yml

@@ -28,6 +28,10 @@ spring:
       max-lifetime: 60000
       connection-timeout: 30000
       pool-name: HikariDataSource
+app:
+  simulatedDelay:
+    enabled: true
+    millis: 3000
 # mybatis-plus 配置
 mybatis-plus:
   configuration: