fix(clients): refresh summary counts after a client mutation

The summary card derived active/bucket counts from the live client_stats snapshot, which only refreshed on the next traffic broadcast (up to 5s). A removal therefore left the counts stale while only total tracked the refetched server summary. Clear the snapshot in invalidateAll so the card falls back to the authoritative server summary immediately; the next stats event repopulates it for live tracking.

frontend/src/hooks/useClients.ts

@@ -264,6 +264,7 @@ export function useClients() {
   const invalidateAll = useCallback(
     () => {
       markLocalInvalidate();
+      setAllClientStats([]);
       return Promise.all([
         queryClient.invalidateQueries({ queryKey: keys.clients.root() }),
         queryClient.invalidateQueries({ queryKey: keys.inbounds.root() }),