feat(复习)：回忆对比优先走 AI 语义对比，失败时降级为内置算法

- CompareResult.java：新增 evaluation 字段（AI 对比时写入评价文本）
- AiServiceClient.java：新增 compareRecall()，调用 lpt-ai /ai/compare-recall
- StandardMindMapServiceImpl.java：recallCompare() 中注入 AiServiceClient，
  优先 try AI 语义对比，含层级上下文和同义表达识别；
  AI 不可用或失败时自动 fallback 到内置标题匹配算法
- StandardMindMapServiceImplTest.java：适配新增的 AiServiceClient 依赖

src/main/java/com/guo/learningprogresstracker/service/impl/AiServiceClient.java

@@ -2,6 +2,7 @@ package com.guo.learningprogresstracker.service.impl;
 
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.guo.learningprogresstracker.utils.CompareResult;
 import jakarta.annotation.PostConstruct;
 import lombok.Setter;
 import lombok.extern.slf4j.Slf4j;
@@ -129,4 +130,40 @@ public class AiServiceClient {
             return Optional.empty();
         }
     }
+
+    /**
+     * 调用 lpt-ai 进行语义化回忆对比。
+     *
+     * @return 带 MATCHED/MISSED 标注和评价文本的对比结果；服务未配置或调用失败时返回 empty
+     */
+    public Optional<CompareResult> compareRecall(String taskName, String standardOutline, String recallOutline) {
+        if (!isConfigured()) {
+            return Optional.empty();
+        }
+        try {
+            Map<String, String> body = Map.of(
+                    "taskName", taskName,
+                    "standardOutline", standardOutline,
+                    "recallOutline", recallOutline
+            );
+
+            HttpRequest request = HttpRequest.newBuilder()
+                    .uri(URI.create(url + "/ai/compare-recall"))
+                    .timeout(Duration.ofSeconds(timeoutSeconds))
+                    .header("Content-Type", "application/json")
+                    .POST(HttpRequest.BodyPublishers.ofString(objectMapper.writeValueAsString(body)))
+                    .build();
+
+            HttpResponse<String> response = httpClient.send(request, HttpResponse.BodyHandlers.ofString());
+            if (response.statusCode() != 200) {
+                log.warn("lpt-ai 回忆对比失败: status={}, body={}", response.statusCode(),
+                        response.body() != null ? response.body().substring(0, Math.min(200, response.body().length())) : "");
+                return Optional.empty();
+            }
+            return Optional.of(objectMapper.readValue(response.body(), CompareResult.class));
+        } catch (Exception e) {
+            log.warn("lpt-ai 回忆对比调用异常，将降级为内置算法: {}", e.getMessage());
+            return Optional.empty();
+        }
+    }
 }