diff --git a/src/main/java/com/yunhai/flowcenter/controller/api/FlowAdminController.java b/src/main/java/com/yunhai/flowcenter/controller/api/FlowAdminController.java
index d132bce..23c0558 100644
--- a/src/main/java/com/yunhai/flowcenter/controller/api/FlowAdminController.java
+++ b/src/main/java/com/yunhai/flowcenter/controller/api/FlowAdminController.java
@@ -102,7 +102,7 @@ public class FlowAdminController {
         return defAdminService.get(adminGuard.requireAdmin(user, null), id);
     }
 
-    /** 保存（新建草稿/编辑；已发布定义保存=升版本，flowGuid 不变；baseGuid=在指定流程线上开新版本草稿） */
+    /** 保存（新建草稿/编辑；已发布定义保存=升版本，flowGuid 不变；baseGuid=在指定流程线上开新版本草稿；changeLog=升版本改动说明，仅新版本行落库，>500 截断） */
     @PostMapping("/def/save")
     public FlwDef defSave(BoaUser user, @RequestBody Map<String, Object> body) {
         Long schId = adminGuard.requireAdmin(user, null);
@@ -110,7 +110,7 @@ public class FlowAdminController {
         return defAdminService.save(schId, id,
                 (String) body.get("code"), (String) body.get("name"),
                 (String) body.get("contentJson"), (String) body.get("baseGuid"),
-                (String) body.get("appKey"));
+                (String) body.get("appKey"), (String) body.get("changeLog"));
     }
 
     /**
@@ -146,6 +146,16 @@ public class FlowAdminController {
         return defAdminService.versions(adminGuard.requireAdmin(user, null), flowGuid);
     }
 
+    /** 在途办件数（议题二④）：flowGuids 逗号分隔，去重后最多 100；返回 flowGuid → 审批中办件数（无在途也返 0 键） */
+    @GetMapping("/def/inflight")
+    public Map<String, Long> defInflight(BoaUser user, @RequestParam("flowGuids") String flowGuids) {
+        Long schId = adminGuard.requireAdmin(user, null);
+        List<String> guids = java.util.Arrays.stream(flowGuids.split(","))
+                .map(String::trim).filter(s -> !s.isEmpty()).distinct().limit(100)
+                .collect(java.util.stream.Collectors.toList());
+        return defAdminService.inflightCounts(schId, guids);
+    }
+
     /** 流程定义示意图（方案 §3.1）：requireAdmin 后按 defId 任意版本出图（草稿可预览） */
     @GetMapping("/def/diagram")
     public FlowModels.DiagramVo defDiagram(BoaUser user, @RequestParam("id") Long id,
diff --git a/src/main/java/com/yunhai/flowcenter/entity/FlwDef.java b/src/main/java/com/yunhai/flowcenter/entity/FlwDef.java
index 13ac96f..f053583 100644
--- a/src/main/java/com/yunhai/flowcenter/entity/FlwDef.java
+++ b/src/main/java/com/yunhai/flowcenter/entity/FlwDef.java
@@ -71,4 +71,8 @@ public class FlwDef extends BaseEntity {
     /** 发布时间 */
     @Column(name = "publish_time")
     private LocalDateTime publishTime;
+
+    /** 升版本改动说明（议题二③，可跳过；仅新版本行有值，草稿直改不写） */
+    @Column(name = "change_log", length = 500)
+    private String changeLog;
 }
diff --git a/src/main/java/com/yunhai/flowcenter/repository/FlwDefRepository.java b/src/main/java/com/yunhai/flowcenter/repository/FlwDefRepository.java
index 521a266..83f11b7 100644
--- a/src/main/java/com/yunhai/flowcenter/repository/FlwDefRepository.java
+++ b/src/main/java/com/yunhai/flowcenter/repository/FlwDefRepository.java
@@ -5,6 +5,7 @@ import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.data.jpa.repository.Query;
 import org.springframework.data.repository.query.Param;
 
+import java.util.Collection;
 import java.util.List;
 import java.util.Optional;
 
@@ -36,4 +37,7 @@ public interface FlwDefRepository extends JpaRepository<FlwDef, Long> {
             + "and d.version = (select max(d2.version) from FlwDef d2 where d2.schId = d.schId "
             + "and d2.flowGuid = d.flowGuid and d2.status = 1) order by d.updateTime desc")
     List<FlwDef> findPublishedLatestPerGuid(@Param("schId") Long schId);
+
+    /** 在途统计（议题二④）：一次取回多条流程线的全部版本行 */
+    List<FlwDef> findBySchIdAndFlowGuidIn(Long schId, Collection<String> flowGuids);
 }
diff --git a/src/main/java/com/yunhai/flowcenter/repository/FlwInstanceRepository.java b/src/main/java/com/yunhai/flowcenter/repository/FlwInstanceRepository.java
index c225ec4..1748828 100644
--- a/src/main/java/com/yunhai/flowcenter/repository/FlwInstanceRepository.java
+++ b/src/main/java/com/yunhai/flowcenter/repository/FlwInstanceRepository.java
@@ -7,6 +7,7 @@ import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.data.jpa.repository.Query;
 import org.springframework.data.repository.query.Param;
 
+import java.util.Collection;
 import java.util.List;
 import java.util.Optional;
 
@@ -39,4 +40,8 @@ public interface FlwInstanceRepository extends JpaRepository<FlwInstance, Long>
             + "and (:status is null or i.status = :status) order by i.id desc")
     Page<FlwInstance> pageByBiz(@Param("schId") Long schId, @Param("bizType") String bizType,
                                 @Param("status") Integer status, Pageable pageable);
+
+    /** 在途办件数（议题二④）：按 def_id 分组统计审批中(10)办件，一行一版本 */
+    @Query("select i.defId, count(i) from FlwInstance i where i.schId = :schId and i.defId in :defIds and i.status = 10 group by i.defId")
+    List<Object[]> countApprovingByDefIds(@Param("schId") Long schId, @Param("defIds") Collection<Long> defIds);
 }
diff --git a/src/main/java/com/yunhai/flowcenter/service/FlowDefAdminService.java b/src/main/java/com/yunhai/flowcenter/service/FlowDefAdminService.java
index ecce6da..ceec023 100644
--- a/src/main/java/com/yunhai/flowcenter/service/FlowDefAdminService.java
+++ b/src/main/java/com/yunhai/flowcenter/service/FlowDefAdminService.java
@@ -18,7 +18,10 @@ import org.springframework.transaction.annotation.Transactional;
 
 import java.time.LocalDateTime;
 import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 import java.util.TreeSet;
 import java.util.UUID;
@@ -36,6 +39,7 @@ public class FlowDefAdminService {
     private final com.yunhai.flowcenter.repository.FlwRouterRepository routerRepository;
     private final com.yunhai.flowcenter.repository.FlwCallbackRegRepository regRepository;
     private final com.yunhai.flowcenter.repository.FlwAppRepository appRepository;
+    private final com.yunhai.flowcenter.repository.FlwInstanceRepository instanceRepository;
     private final FlowDeptAdminService deptAdminService;
     private final FlowEngine flowEngine;
     private final ObjectMapper objectMapper;
@@ -77,9 +81,13 @@ public class FlowDefAdminService {
      * - id 空：永远新开一条流程线（flowGuid 生成，version=1）；同编码多条线合法，前端保存前有软提示
      * appKey=归属应用（筛选维度，2026-10-12 拍板必填）：新建必须显式传；升版本/直改可继承源行，
      * 但源行为空时必须显式补填——存量 NULL 线随编辑自然收敛（白名单只校验显式传入值，继承值不重校）
+     * changeLog=升版本改动说明（议题二③）：只随新建行落库（三个建新行分支），草稿直改行不写也不清空
      */
     @Transactional
-    public FlwDef save(Long schId, Long id, String code, String name, String contentJson, String baseGuid, String appKey) {
+    public FlwDef save(Long schId, Long id, String code, String name, String contentJson,
+                      String baseGuid, String appKey, String changeLog) {
+        String cleanLog = (changeLog == null || changeLog.trim().isEmpty()) ? null
+                : changeLog.trim().substring(0, Math.min(500, changeLog.trim().length()));
         String cleanAppKey = (appKey == null || appKey.trim().isEmpty()) ? null : appKey.trim();
         // 归属应用白名单（2026-10-10 应用设置）：显式传入非空时必须 ∈ flw_app(sch, enabled=1)；
         // 继承值不重校（既成事实，应用停用不应卡死升版本）。不在校池/未开启的应用由此拦下（拍板 D2：不做存量兜底）
@@ -141,6 +149,10 @@ public class FlowDefAdminService {
             throw new BizException(ErrorCode.PARAM_ERROR,
                     "归属应用必填：请选择归属应用后再保存（应用需先在 流程管理 > 应用设置 中开启）");
         }
+        // 改动说明只写新建行（新建/baseGuid 开版/已发布复制升版三分支 id 必为 null）；草稿直改不动
+        if (def.getId() == null) {
+            def.setChangeLog(cleanLog);
+        }
         def.setContentJson(contentJson);
         // 定义 JSON 里的 code/name 与行字段一致性校验（给绑定回显用行字段，JSON 内为主）
         if (parsed.code != null && !parsed.code.trim().isEmpty() && !parsed.code.trim().equals(def.getCode())) {
@@ -205,6 +217,23 @@ public class FlowDefAdminService {
         return defRepository.findBySchIdAndFlowGuidOrderByVersionDesc(schId, flowGuid);
     }
 
+    /** 在途办件数（议题二④）：flowGuid → 审批中(10)办件数；口径=def_id 精确匹配该线各版本；请求的 guid 全部有键（无在途=0） */
+    public Map<String, Long> inflightCounts(Long schId, Collection<String> flowGuids) {
+        Map<String, Long> result = new HashMap<>();
+        if (flowGuids == null || flowGuids.isEmpty()) return result;
+        flowGuids.forEach(g -> result.put(g, 0L));
+        List<FlwDef> defs = defRepository.findBySchIdAndFlowGuidIn(schId, flowGuids);
+        if (defs.isEmpty()) return result;
+        Map<Long, String> idToGuid = new HashMap<>();
+        defs.forEach(d -> idToGuid.put(d.getId(), d.getFlowGuid()));
+        instanceRepository.countApprovingByDefIds(schId, idToGuid.keySet()).forEach(r -> {
+            Long defId = ((Number) r[0]).longValue();
+            Long cnt = ((Number) r[1]).longValue();
+            result.merge(idToGuid.get(defId), cnt, Long::sum);
+        });
+        return result;
+    }
+
     /**
      * 元数据原地编辑（2026-10-10 四议题·议题2，拍板 D4）：已发布/停用/草稿均可只改 name/appKey
      * 而<b>不升版本</b>——结构改动仍走 save 的升版本路径，两者完全隔离（本方法不碰
diff --git a/src/main/java/com/yunhai/flowcenter/service/FlowQueryService.java b/src/main/java/com/yunhai/flowcenter/service/FlowQueryService.java
index 20e2a44..cee4437 100644
--- a/src/main/java/com/yunhai/flowcenter/service/FlowQueryService.java
+++ b/src/main/java/com/yunhai/flowcenter/service/FlowQueryService.java
@@ -383,6 +383,9 @@ public class FlowQueryService {
         row.put("attempt", r.getAttempt());
         row.put("status", null);
         row.put("time", str(r.getDecideTime()));
+        // 议题三②：调试弹窗「从路由日志导入」需要看失败摘要（>500 截断）
+        row.put("rawResponse", r.getRawResponse() == null ? "" :
+                (r.getRawResponse().length() > 500 ? r.getRawResponse().substring(0, 500) + "…" : r.getRawResponse()));
         return row;
     }
 
diff --git a/src/main/resources/sql/20261012_add_flw_def_change_log.sql b/src/main/resources/sql/20261012_add_flw_def_change_log.sql
new file mode 100644
index 0000000..79566e8
--- /dev/null
+++ b/src/main/resources/sql/20261012_add_flw_def_change_log.sql
@@ -0,0 +1,4 @@
+-- 2026-10-12 议题二：升版本改动说明（版本行即说明；独立版本日志表留 P2）
+-- ddl-auto=update 会自动加列；本脚本为生产备案（生产建议停自动 DDL 后手工执行）
+ALTER TABLE `flw_def`
+  ADD COLUMN `change_log` VARCHAR(500) NULL COMMENT '升版本改动说明（可跳过；NULL=未填写）' AFTER `name`;