fix(cluster): stop saying "waiting for spots" when 76 have arrived

An operator sent two screenshots: 76 LIVE in the counter, and the panel beside
it reading "Waiting for spots… Spots will appear as the cluster sends them."
Both his band and mode were locked to the rig — 20 m, SSB — so the filters were
doing exactly their job and the empty state was describing a different problem
entirely. He went looking for a connection fault.

It now says how many arrived, names every filter currently narrowing the list,
and offers one button to clear them all. The band and mode locks are named
first: they follow the rig rather than a click, so they are the two nobody
remembers switching on.

Also times the connection. He reports the first launch taking a while to
produce spots and a restart connecting instantly, which is the signature of a
slow name resolution rather than a slow node — the OS caches the answer, so the
second run skips it. The log now carries the dial duration and the delay to the
first spot, which separates that from a node that simply had nothing to say.
Hypothesis, not conclusion: the next log settles it.

changelog.json

@@ -3,10 +3,14 @@
     "version": "0.25.4",
     "date": "",
     "en": [
-      "WinKeyer: the opening probe goes out as one write, matching a capture of a client that talks to the same K3NG keyer, and the handshake bytes are always logged so a keyer that stays silent can be diagnosed."
+      "WinKeyer: the opening probe goes out as one write, matching a capture of a client that talks to the same K3NG keyer, and the handshake bytes are always logged so a keyer that stays silent can be diagnosed.",
+      "DX cluster: when spots arrive and every one is filtered out, the panel says so, names the filters doing it and offers to clear them — it used to say “waiting for spots” beside a counter reading 76 live.",
+      "DX cluster: the log times the connection and the first spot, so a slow first launch can be told apart from a quiet node."
     ],
     "fr": [
-      "WinKeyer : la sonde d’ouverture part en un seul envoi, calquée sur la capture d’un client qui dialogue avec le même manipulateur K3NG, et les octets de la poignée de main sont toujours journalisés pour diagnostiquer un manipulateur muet."
+      "WinKeyer : la sonde d’ouverture part en un seul envoi, calquée sur la capture d’un client qui dialogue avec le même manipulateur K3NG, et les octets de la poignée de main sont toujours journalisés pour diagnostiquer un manipulateur muet.",
+      "Cluster DX : quand des spots arrivent et que tout est filtré, le panneau le dit, nomme les filtres responsables et propose de les effacer — il affichait « en attente de spots » à côté d’un compteur à 76 en direct.",
+      "Cluster DX : le journal chronomètre la connexion et le premier spot, pour distinguer un premier lancement lent d’un nœud silencieux."
     ]
   },
   {