fix: avoid Convex skip sentinel in queries

src/components/portal/portal-ticket-list.tsx

@@ -21,14 +21,14 @@ export function PortalTicketList() {
   const viewerId = (convexUserId ?? machineContext?.assignedUserId ?? null) as Id<"users"> | null
 
   const ticketsRaw = useQuery(
-    api.tickets.list,
+    viewerId ? api.tickets.list : undefined,
     viewerId
       ? {
           tenantId: session?.user.tenantId ?? DEFAULT_TENANT_ID,
           viewerId,
           limit: 100,
         }
-      : "skip"
+      : undefined
   )
 
   const tickets = useMemo(() => {