fix: harden group lifecycle and registration writes

server/im_http.go

@@ -6210,6 +6210,14 @@ func serveIMGroupOwnerTransfer(wrt http.ResponseWriter, req *http.Request, topic
 	}
 	if err = store.GroupBusiness.TransferOwner(principal.TenantID, topic, principal.Uid, target,
 		body.Version, time.Now().UTC().Round(time.Millisecond)); err != nil {
+		if errors.Is(err, types.ErrInvalidResponse) {
+			currentVersion := 0
+			if settings, settingsErr := store.GroupBusiness.GetSettings(principal.TenantID, topic); settingsErr == nil && settings != nil {
+				currentVersion = settings.Version
+			}
+			writeIMError(wrt, req, http.StatusConflict, 30006, "VERSION_CONFLICT", "version conflict", map[string]any{"current_version": currentVersion})
+			return
+		}
 		writeIMRelationError(wrt, req, err)
 		return
 	}
@@ -7996,9 +8004,8 @@ func mergeGroupSettingsPayload(payload map[string]any, settings *types.GroupSett
 	payload["description"] = settings.Description
 	payload["owner"] = settings.OwnerUserID.UserId()
 	payload["member_count"] = settings.MemberCount
-	if _, exists := payload["version"]; !exists {
-		payload["version"] = settings.Version
-	}
+	payload["status"] = settings.GroupStatus
+	payload["version"] = settings.Version
 	return payload
 }