feat(t14-s345): 群迁移 + 消息迁移 + 关系链迁移

T14 S3/S4/S5 阶段：
- S3 群迁移：getAppidGroups/getGroupInfo（老密钥拉）+ createGroup/addGroupMember（主密钥导入）+ migrateGroups
- S4 消息迁移：importMsg/importGroupMsg + migrateMessages（会话清单+断点续传，v1 最近7天/100条）
- S5 关系链：importFriend/friendGetList（sns 系列）+ migrateRoster
- 后台 /admin/migrate/{groups,messages,roster} 触发 + migrate.ftl 三表单

S1/S2 完整联调通过；S3/S4/S5 代码完成+通路验证（腾讯返业务响应），
核心导入待真实老应用（10003 群组/60008 消息/60002 关系链）。

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

src/main/java/com/imutil/controller/AdminController.java

@@ -321,12 +321,14 @@ public class AdminController {
     @Get
     @Mapping("/migrate")
     public Object migratePage(@Param(defaultValue = "") String msg,
-                              @Param(defaultValue = "") String imported) {
+                              @Param(defaultValue = "") String imported,
+                              @Param(defaultValue = "") String migrated) {
         ModelAndView mv = view("migrate.ftl", "数据迁移", "migrate");
         mv.put("tasks", migrateService.listTasks());
         mv.put("apps", sourceAppService.list());
         mv.put("msg", msg);
         mv.put("imported", imported);
+        mv.put("migrated", migrated);
         return mv;
     }
 
@@ -357,6 +359,71 @@ public class AdminController {
         ctx.redirect(basePath + "/admin/migrate?msg=done&imported=" + task.getProcessedCount());
     }
 
+    /**
+     * 群迁移：选老应用 → getAppidGroups 拉群 → 逐群拉成员 → 加前缀建群 → 导入成员 → 写 group_mapping
+     */
+    @Post
+    @Mapping("/migrate/groups")
+    public void migrateGroups(@Param Long sourceAppId, Context ctx) throws Throwable {
+        if (sourceAppId == null) {
+            ctx.redirect(basePath + "/admin/migrate?msg=noapp");
+            return;
+        }
+        MigrateTask task = migrateService.migrateGroups(sourceAppId);
+        ctx.redirect(basePath + "/admin/migrate?msg=gdone&migrated=" + task.getProcessedCount());
+    }
+
+    /**
+     * 单聊消息迁移：上传会话清单（每行 from,to）或粘贴 → getRoamMsg 拉 → 加前缀 → importMsg
+     */
+    @Post
+    @Mapping("/migrate/messages")
+    public void migrateMessages(@Param Long sourceAppId,
+                                @Param(defaultValue = "") String convText,
+                                Context ctx) throws Throwable {
+        UploadedFile file = ctx.file("file");
+        String content = file != null ? new String(file.getContentAsBytes(), StandardCharsets.UTF_8) : convText;
+        List<String[]> pairs = new ArrayList<>();
+        parseConvPairs(content, pairs);
+        if (sourceAppId == null) {
+            ctx.redirect(basePath + "/admin/migrate?msg=noapp");
+            return;
+        }
+        if (pairs.isEmpty()) {
+            ctx.redirect(basePath + "/admin/migrate?msg=empty");
+            return;
+        }
+        MigrateTask task = migrateService.migrateMessages(sourceAppId, pairs);
+        ctx.redirect(basePath + "/admin/migrate?msg=mdone&imported=" + task.getProcessedCount());
+    }
+
+    /**
+     * 关系链迁移：上传用户清单（每行一个 UserID）或粘贴 → 逐用户拉好友 → 加前缀 → importFriend
+     */
+    @Post
+    @Mapping("/migrate/roster")
+    public void migrateRoster(@Param Long sourceAppId,
+                              @Param(defaultValue = "") String userText,
+                              Context ctx) throws Throwable {
+        UploadedFile file = ctx.file("file");
+        List<String> userIds = new ArrayList<>();
+        if (file != null) {
+            parseUserIds(new String(file.getContentAsBytes(), StandardCharsets.UTF_8), userIds);
+        } else if (!userText.isEmpty()) {
+            parseUserIds(userText, userIds);
+        }
+        if (sourceAppId == null) {
+            ctx.redirect(basePath + "/admin/migrate?msg=noapp");
+            return;
+        }
+        if (userIds.isEmpty()) {
+            ctx.redirect(basePath + "/admin/migrate?msg=empty");
+            return;
+        }
+        MigrateTask task = migrateService.migrateRoster(sourceAppId, userIds);
+        ctx.redirect(basePath + "/admin/migrate?msg=rdone&imported=" + task.getProcessedCount());
+    }
+
     /** 解析用户清单：每行一个 UserID，空行与 # 注释跳过 */
     private void parseUserIds(String content, List<String> out) {
         for (String line : content.split("\\r?\\n")) {
@@ -367,6 +434,23 @@ public class AdminController {
         }
     }
 
+    /** 解析会话清单：每行 from,to（逗号或空格分隔），空行与 # 注释跳过 */
+    private void parseConvPairs(String content, List<String[]> out) {
+        if (content == null || content.isEmpty()) {
+            return;
+        }
+        for (String line : content.split("\\r?\\n")) {
+            line = line.trim();
+            if (line.isEmpty() || line.startsWith("#")) {
+                continue;
+            }
+            String[] parts = line.split("[,，\\s]+");
+            if (parts.length >= 2) {
+                out.add(new String[]{parts[0], parts[1]});
+            }
+        }
+    }
+
     // ==================== 公共：构造页面模型 ====================
 
     /**