fix(clients): persist group for node-inbound clients

The client create/edit form left `group` out of the request payload, so choosing a group in the form was silently dropped (bulkAdd from the Groups page still worked because it writes the column directly). Add `group` to the payload next to `comment`.

SyncInbound also overwrote group_name unconditionally; a group set via bulkAdd is never pushed to the node, so the next node snapshot — which lacks it — wiped the column. Keep group sticky (only overwrite when the incoming value is non-empty); group is only ever set/cleared via the Groups page. Preserve comment for node clients during snapshot sync the same way. Add tests.

web/service/inbound.go

@@ -1589,6 +1589,32 @@ func (s *InboundService) setRemoteTrafficLocked(nodeID int, snap *runtime.Traffi
 			}
 			filtered = append(filtered, clients[i])
 		}
+		localEmails := make([]string, 0, len(filtered))
+		for i := range filtered {
+			if filtered[i].Email != "" {
+				localEmails = append(localEmails, filtered[i].Email)
+			}
+		}
+		if len(localEmails) > 0 {
+			var localMeta []struct {
+				Email   string
+				Comment string `gorm:"column:comment"`
+			}
+			if err := tx.Table("clients").
+				Select("email, comment").
+				Where("email IN ?", localEmails).
+				Find(&localMeta).Error; err == nil {
+				commentByEmail := make(map[string]string, len(localMeta))
+				for _, m := range localMeta {
+					commentByEmail[m.Email] = m.Comment
+				}
+				for i := range filtered {
+					if cmt, ok := commentByEmail[filtered[i].Email]; ok {
+						filtered[i].Comment = cmt
+					}
+				}
+			}
+		}
 		if err := s.clientService.SyncInbound(tx, c.Id, filtered); err != nil {
 			logger.Warningf("setRemoteTraffic: sync clients for tag %q failed: %v", snapIb.Tag, err)
 		}