feat(复习): 支持会话维度复习 + 标准导图按会话过滤（后端）

- MindMapNode 新增 sessionNum 字段
- BuiltinMindMapGenerator 生成节点时填充 sessionNum
- MindMapTreeTool.filterBySession() 按会话过滤标准导图
- recallCompare 接受 sessionNum 参数
- ReviewRecallRecordEntity 新增 sessionNum 字段
- Flyway V20260705_1: review_recall_records 加 session_num 列
- 新增 GET /study-sessions/tasks/{taskNum}/sessions 端点

src/main/java/com/guo/learningprogresstracker/controller/ReviewController.java

@@ -154,7 +154,7 @@ public class ReviewController {
     public CommonResult<ReviewStandardMindMapEntity> recallCompare(
             @PathVariable String taskNum,
             @Valid @RequestBody RecallCompareRequest request) throws NotFindEntitiesException, OperationFailedException {
-        return CommonResult.success(standardMindMapService.recallCompare(taskNum, request.getRecallOutline()));
+        return CommonResult.success(standardMindMapService.recallCompare(taskNum, request.getRecallOutline(), request.getSessionNum()));
     }
 
     /**

src/main/java/com/guo/learningprogresstracker/controller/StudySessionController.java

@@ -18,7 +18,9 @@ import lombok.RequiredArgsConstructor;
 import org.springframework.validation.annotation.Validated;
 import org.springframework.web.bind.annotation.*;
 
+import com.guo.learningprogresstracker.dto.response.SessionBriefVO;
 import java.util.ArrayList;
+import java.util.List;
 import java.time.LocalDateTime;
 
 /**
@@ -137,4 +139,10 @@ public class StudySessionController {
             @RequestParam(required = false) String excludeTaskNum) {
         return CommonResult.success(studySessionsServiceImpl.getActiveSession(excludeTaskNum));
     }
+
+    /** 获取任务的所有会话简要列表（用于复习维度选择） */
+    @GetMapping("/tasks/{taskNum}/sessions")
+    public CommonResult<List<SessionBriefVO>> getTaskSessions(@PathVariable String taskNum) {
+        return CommonResult.success(studySessionsServiceImpl.getTaskSessions(taskNum));
+    }
 }

src/main/java/com/guo/learningprogresstracker/dto/request/RecallCompareRequest.java

@@ -11,4 +11,7 @@ public class RecallCompareRequest {
 
     @NotBlank(message = "回忆大纲不可为空")
     private String recallOutline;
+
+    /** 复习维度：会话编码，null 为任务维度 */
+    private String sessionNum;
 }

src/main/java/com/guo/learningprogresstracker/dto/response/SessionBriefVO.java

@@ -0,0 +1,15 @@
+package com.guo.learningprogresstracker.dto.response;
+
+import lombok.Data;
+
+/**
+ * 会话简要信息（用于复习维度选择列表）
+ */
+@Data
+public class SessionBriefVO {
+    private String sessionNum;
+    private String startTime;
+    private String expectation;
+    private int reportCount;
+    private int fragmentCount;
+}

src/main/java/com/guo/learningprogresstracker/entity/ReviewRecallRecordEntity.java

@@ -24,6 +24,12 @@ public class ReviewRecallRecordEntity extends BaseEntity implements Serializable
     @TableField(value = "standard_map_id")
     private Integer standardMapId;
 
+    /**
+     * 复习维度：会话编码（null 表示任务维度复习）
+     */
+    @TableField(value = "session_num")
+    private String sessionNum;
+
     /**
      * 用户回忆绘制的导图大纲文本
      */

src/main/java/com/guo/learningprogresstracker/service/StandardMindMapService.java

@@ -32,9 +32,10 @@ public interface StandardMindMapService {
      * 用户提交回忆大纲，与标准导图对比并返回结果。
      *
      * @param recallOutline 用户回忆的缩进大纲文本
+     * @param sessionNum    可选会话编码，指定时仅对比该会话相关的标准导图节点
      * @return 对比记录实体（compareResult 字段包含对比树 JSON）
      */
-    ReviewStandardMindMapEntity recallCompare(String taskNum, String recallOutline) throws NotFindEntitiesException, OperationFailedException;
+    ReviewStandardMindMapEntity recallCompare(String taskNum, String recallOutline, String sessionNum) throws NotFindEntitiesException, OperationFailedException;
 
     /**
      * 获取该任务的所有回忆对比记录。

src/main/java/com/guo/learningprogresstracker/service/StudySessionsService.java

@@ -11,7 +11,9 @@ import com.baomidou.mybatisplus.extension.service.IService;
 import com.guo.learningprogresstracker.exception.ErrorParameterException;
 
 import java.time.LocalDateTime;
+import com.guo.learningprogresstracker.dto.response.SessionBriefVO;
 import java.util.ArrayList;
+import java.util.List;
 
 /**
 * @author guo
@@ -35,4 +37,7 @@ public interface StudySessionsService extends IService<StudySessionsEntity> {
     Page<StudyReportsEntity> getTaskReports(String taskNum, int page, int size, String keyword);
 
     StudySessionResponse getActiveSession(String excludeTaskNum);
+
+    /** 获取任务的所有会话简要信息（复习维度选择用） */
+    List<SessionBriefVO> getTaskSessions(String taskNum);
 }

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

@@ -84,6 +84,7 @@ public class BuiltinMindMapGenerator implements MindMapAiClient {
             }
 
             MindMapNode sessionNode = new MindMapNode(sessionTitle);
+            sessionNode.setSessionNum(sessionNum);
 
             // 报告作为子节点
             for (StudyReportsEntity report : sessReports) {
@@ -93,6 +94,7 @@ public class BuiltinMindMapGenerator implements MindMapAiClient {
                 reportNode.setNotes(content);
                 reportNode.setSourceType("REPORT");
                 reportNode.setSourceId(report.getId());
+                reportNode.setSessionNum(sessionNum);
                 sessionNode.getChildren().add(reportNode);
             }
 
@@ -104,6 +106,7 @@ public class BuiltinMindMapGenerator implements MindMapAiClient {
                 fragNode.setNotes(content);
                 fragNode.setSourceType("FRAGMENT");
                 fragNode.setSourceId(frag.getId());
+                fragNode.setSessionNum(sessionNum);
                 sessionNode.getChildren().add(fragNode);
             }
 

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

@@ -96,7 +96,7 @@ public class StandardMindMapServiceImpl implements StandardMindMapService {
 
     @Override
     @Transactional
-    public ReviewStandardMindMapEntity recallCompare(String taskNum, String recallOutline)
+    public ReviewStandardMindMapEntity recallCompare(String taskNum, String recallOutline, String sessionNum)
             throws NotFindEntitiesException, OperationFailedException {
         ensureTaskExists(taskNum);
 
@@ -107,6 +107,11 @@ public class StandardMindMapServiceImpl implements StandardMindMapService {
         MindMapNode standardRoot = MindMapTreeTool.fromJson(standard.getContent(), objectMapper);
         MindMapNode recallRoot = MindMapTreeTool.parseOutline(recallOutline);
 
+        // 2b. 若指定了会话维度，过滤标准导图只保留该会话相关节点
+        if (sessionNum != null && !sessionNum.isBlank()) {
+            standardRoot = MindMapTreeTool.filterBySession(standardRoot, sessionNum);
+        }
+
         // 3. 执行对比（优先 AI 语义对比，失败时降级为内置算法）
         CompareResult result;
         if (aiServiceClient.isConfigured()) {
@@ -142,6 +147,7 @@ public class StandardMindMapServiceImpl implements StandardMindMapService {
         ReviewRecallRecordEntity record = new ReviewRecallRecordEntity();
         record.setTaskNum(taskNum);
         record.setStandardMapId(standard.getId());
+        record.setSessionNum(sessionNum != null && !sessionNum.isBlank() ? sessionNum : null);
         record.setRecallContent(recallOutline);
         record.setCompareResult(resultJson);
         record.setRecallRatio(result.getRecallRatio());

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

@@ -5,6 +5,7 @@ import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
 import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
 import com.google.protobuf.ServiceException;
 import com.guo.learningprogresstracker.dto.StudySessionsDto;
+import com.guo.learningprogresstracker.dto.response.SessionBriefVO;
 import com.guo.learningprogresstracker.dto.response.StudySessionResponse;
 import com.guo.learningprogresstracker.entity.StudyReportFragmentsEntity;
 import com.guo.learningprogresstracker.entity.StudyReportsEntity;
@@ -26,6 +27,7 @@ import org.springframework.transaction.annotation.Transactional;
 
 import java.time.LocalDateTime;
 import java.util.ArrayList;
+import java.util.List;
 import java.util.Optional;
 import java.util.stream.Collectors;
 
@@ -225,6 +227,34 @@ public class StudySessionsServiceImpl extends ServiceImpl<StudySessionsMapper, S
         return result;
     }
 
+    // ============ 获取任务会话列表（复习维度选择用） ============
+
+    @Override
+    public List<SessionBriefVO> getTaskSessions(String taskNum) {
+        var sessions = this.list(Wrappers.lambdaQuery(StudySessionsEntity.class)
+                .eq(StudySessionsEntity::getTaskNum, taskNum)
+                .orderByDesc(StudySessionsEntity::getStartTime));
+
+        return sessions.stream().map(s -> {
+            SessionBriefVO vo = new SessionBriefVO();
+            vo.setSessionNum(s.getSessionNum());
+            vo.setStartTime(s.getStartTime() != null ? s.getStartTime().toString() : null);
+            // 查询该会话的预期
+            Optional.ofNullable(studyExpectationsService.getBySessionNum(s.getSessionNum()))
+                    .ifPresent(e -> vo.setExpectation(e.getDescription()));
+            // 统计报告和残片数量
+            long reportCount = studyReportsMapper.selectCount(
+                    Wrappers.lambdaQuery(StudyReportsEntity.class)
+                            .eq(StudyReportsEntity::getSessionNum, s.getSessionNum()));
+            long fragmentCount = studyReportFragmentsMapper.selectCount(
+                    Wrappers.lambdaQuery(StudyReportFragmentsEntity.class)
+                            .eq(StudyReportFragmentsEntity::getSessionNum, s.getSessionNum()));
+            vo.setReportCount((int) reportCount);
+            vo.setFragmentCount((int) fragmentCount);
+            return vo;
+        }).collect(Collectors.toList());
+    }
+
     // ============ 活跃会话查询 ============
 
     /**

src/main/java/com/guo/learningprogresstracker/utils/MindMapNode.java

@@ -35,6 +35,8 @@ public class MindMapNode {
     private String notes;
     private String sourceType;
     private Integer sourceId;
+    /** 可选：节点来源会话编码（REPORT/FRAGMENT 节点使用） */
+    private String sessionNum;
     private List<MindMapNode> children;
 
     public MindMapNode(String title) {
@@ -51,6 +53,7 @@ public class MindMapNode {
         map.put("notes", notes != null ? notes : "");
         if (sourceType != null) map.put("sourceType", sourceType);
         if (sourceId != null) map.put("sourceId", sourceId);
+        if (sessionNum != null) map.put("sessionNum", sessionNum);
         List<Object> childMaps = new ArrayList<>();
         if (children != null) {
             for (MindMapNode c : children) {
@@ -70,6 +73,7 @@ public class MindMapNode {
         if (map.containsKey("sourceId") && map.get("sourceId") != null) {
             node.setSourceId(((Number) map.get("sourceId")).intValue());
         }
+        node.setSessionNum((String) map.get("sessionNum"));
         Object raw = map.getOrDefault("children", map.get("nodes"));
         List<MindMapNode> children = new ArrayList<>();
         if (raw instanceof List<?> list) {

src/main/java/com/guo/learningprogresstracker/utils/MindMapTreeTool.java

@@ -156,6 +156,61 @@ public class MindMapTreeTool {
         return 1 + node.getChildren().stream().mapToInt(MindMapTreeTool::maxDepth).max().orElse(0);
     }
 
+    /**
+     * 过滤树：只保留与指定 sessionNum 相关的分支。
+     * - 节点有 sessionNum 且匹配 → 保留
+     * - 节点无 sessionNum（如 APPLICATION 或 AI 生成的节点） → 保留（视为任务级通用知识）
+     * - 有子节点被保留时，父节点也保留
+     *
+     * @param root       树根
+     * @param sessionNum 目标会话编码
+     * @return 过滤后的树，若无相关节点则返回仅含根的空树
+     */
+    public static MindMapNode filterBySession(MindMapNode root, String sessionNum) {
+        if (root == null || sessionNum == null || sessionNum.isBlank()) return root;
+        MindMapNode filtered = filterRecursive(root, sessionNum);
+        return filtered != null ? filtered : new MindMapNode(root.getTitle() != null ? root.getTitle() : "");
+    }
+
+    private static MindMapNode filterRecursive(MindMapNode node, String sessionNum) {
+        if (node == null) return null;
+
+        // 先过滤子节点
+        List<MindMapNode> keptChildren = new ArrayList<>();
+        if (node.getChildren() != null) {
+            for (MindMapNode child : node.getChildren()) {
+                MindMapNode kept = filterRecursive(child, sessionNum);
+                if (kept != null) {
+                    keptChildren.add(kept);
+                }
+            }
+        }
+
+        // 判断当前节点是否应该保留：
+        // 1. 有 sessionNum 且匹配 → 保留
+        // 2. 无 sessionNum → 保留（任务级节点，如 APPLICATION 或 AI 生成）
+        // 3. 有子节点保留 → 保留
+        boolean selfMatch = (node.getSessionNum() == null) || sessionNum.equals(node.getSessionNum());
+        if (selfMatch || !keptChildren.isEmpty()) {
+            MindMapNode result = copyNodeShallow(node);
+            result.setChildren(keptChildren.isEmpty() ? node.getChildren() : keptChildren);
+            return result;
+        }
+
+        return null;
+    }
+
+    /** 浅拷贝节点（仅拷贝标量字段，不拷贝 children） */
+    private static MindMapNode copyNodeShallow(MindMapNode node) {
+        MindMapNode copy = new MindMapNode();
+        copy.setTitle(node.getTitle());
+        copy.setNotes(node.getNotes());
+        copy.setSourceType(node.getSourceType());
+        copy.setSourceId(node.getSourceId());
+        copy.setSessionNum(node.getSessionNum());
+        return copy;
+    }
+
     /** 序列化整棵树为 JSON */
     public static String toJson(MindMapNode root, ObjectMapper mapper) {
         try {