feat: progress bar for bulk QSO updates from QRZ.com

Selecting the 102 contacts of a freshly imported contest log and updating them
from QRZ.com is 102 network round trips. Nothing moved on screen while it ran,
so the only honest reading was that the application had frozen — and the natural
response to that is to kill it, halfway through.

The backend now emits a progress event per QSO and the frontend shows the same
overlay the ADIF import uses: a bar, the count, and the callsign being queried.

The callsign is reported BEFORE the lookup rather than after. With a slow
provider that is the difference between "waiting on F4BPO" and a name that lags
one QSO behind whatever is actually taking the time — which would be the field
someone stares at while deciding whether it is stuck.

The overlay is cleared by the closing event and again in a finally, so neither
a completed run nor a failed one can leave it on screen.

changelog.json

@@ -5,12 +5,14 @@
     "en": [
       "The Kenwood backend is now exercised against a rig that answers: OpsLog talks to the TS-2000 emulator it already carries for ACOM amplifiers, so frequency, mode, VFO, split and PTT are checked end to end. Testing on a real Kenwood is still needed, but the dialogue itself is no longer untried.",
       "Kenwood: split is now detected from the transmit and receive VFO (FR/FT) when the radio leaves it out of its status frame — the case seen on a Flex in Kenwood CAT mode, where the frequency read correctly but split never appeared. Radios that report it in the status frame are unaffected.",
-      "The CAT protocol trace covers the Kenwood backend as well, not just CI-V. Settings → CAT."
+      "The CAT protocol trace covers the Kenwood backend as well, not just CI-V. Settings → CAT.",
+      "Updating selected QSOs from QRZ.com now shows a progress bar with the callsign being queried. On a contest log freshly imported, a hundred contacts mean a hundred network round trips, and until now nothing moved on screen while it worked."
     ],
     "fr": [
       "Le backend Kenwood est désormais éprouvé face à une radio qui répond : OpsLog dialogue avec l'émulateur TS-2000 qu'il embarque déjà pour les amplis ACOM, ce qui vérifie fréquence, mode, VFO, split et PTT de bout en bout. Un essai sur un vrai Kenwood reste nécessaire, mais le dialogue n'est plus non testé.",
       "Kenwood : le split est désormais détecté à partir des VFO d'émission et de réception (FR/FT) quand la radio ne le renseigne pas dans sa trame d'état — le cas observé sur un Flex en mode CAT Kenwood, où la fréquence était juste mais le split n'apparaissait jamais. Les radios qui le signalent normalement ne changent pas.",
-      "La trace du protocole CAT couvre aussi le backend Kenwood, plus seulement le CI-V. Réglages → CAT."
+      "La trace du protocole CAT couvre aussi le backend Kenwood, plus seulement le CI-V. Réglages → CAT.",
+      "La mise à jour des QSO sélectionnés depuis QRZ.com affiche désormais une barre de progression avec l'indicatif en cours d'interrogation. Sur un log de concours fraîchement importé, cent contacts font cent allers-retours réseau, et jusqu'ici rien ne bougeait à l'écran pendant ce temps."
     ]
   },
   {