fix: start system default sync channels by default

Create and restart paths enable IsSystemDefault channels; SyncPage auto-starts after save.

Co-authored-by: Cursor <cursoragent@cursor.com>

platform/internal/logic/applogic/bind_flow.go

@@ -57,6 +57,7 @@ func (l *AuthLogic) CreateBindCode(req BindCodeCreateReq) (*bindcodestore.BindCo
 			if online == "" {
 				online = dbsync.ResolveOnlineDBID("", ch.ID)
 			}
+			_ = l.svcCtx.DBSync.StartChannel(ch.ID) // 已有默认同步通道也保持运行中
 		} else {
 			// 尝试创建默认同步通道
 			cfg := l.svcCtx.Config.DBSync
@@ -64,7 +65,7 @@ func (l *AuthLogic) CreateBindCode(req BindCodeCreateReq) (*bindcodestore.BindCo
 			if driver == "" {
 				driver = dbsync.DriverPostgres
 			}
-			saved, err := l.svcCtx.DBSync.Store().EnsureSystemDefaultChannel(dbsync.DefaultChannelOpts{
+			saved, err := l.svcCtx.DBSync.EnsureAndStartSystemDefaultChannel(dbsync.DefaultChannelOpts{
 				TenantID:     tid,
 				RemoteDriver: driver,
 				RemoteDSN:    strings.TrimSpace(cfg.DefaultRemoteDSN),