fix(cluster): refresh spot statuses by merge, not by clearing the cache

setSpotStatus({}) blanked EVERY spot's status, so logging one contact wiped all
the other NEW/NEW-BAND badges and they popped back a moment later. Instead,
re-fetch the shown spots and OVERWRITE each status in place (merge) — the just-
worked spot updates while the rest stay put, no flicker. Same visibility gate
and 2 s debounce; backend cost is one status batch (one logbook scan) as before.

frontend/src/App.tsx

@@ -1500,34 +1500,67 @@ export default function App() {
   // still need resolving without re-subscribing the cluster:spot listener.
   const spotStatusRef = useRef(spotStatus);
   useEffect(() => { spotStatusRef.current = spotStatus; }, [spotStatus]);
-  // After a QSO is logged, the call/entity/POTA/prefix/slot just worked is no
-  // longer "new" — but each spot's status is cached and never expires, so the
-  // cluster kept showing the old NEW badge until a restart. Dropping the cache
-  // re-evaluates every visible spot against the fresh logbook (the poll refetches
-  // the now-unknown statuses). Kept CHEAP for old machines / big logbooks:
-  //   • only when the cluster is actually on screen — otherwise it costs nothing;
-  //   • a log made while it's hidden just marks it dirty and refetches ONCE the
-  //     next time you open the cluster;
-  //   • debounced, so a fast run coalesces instead of re-scanning per QSO.
+  // Mirror of spots so the log-triggered refresh reads the current list without
+  // a stale closure.
+  const spotsRef = useRef(spots);
+  useEffect(() => { spotsRef.current = spots; }, [spots]);
+  // Re-fetch the status of every SHOWN spot and OVERWRITE the cache (merge, never
+  // clear). Overwriting keeps the other NEW badges on screen until their fresh
+  // value lands, instead of blanking the whole grid and letting the badges pop
+  // back a moment later. The backend cost is one status batch regardless of spot
+  // count (it scans the logbook once), so this is as cheap as the poll already is.
+  const refreshSpotStatuses = useCallback(async () => {
+    const cur = spotsRef.current;
+    if (!cur.length) return;
+    const queries: { call: string; band: string; mode: string; pota_ref: string }[] = [];
+    const seen = new Set<string>();
+    for (const s of cur) {
+      const k = spotStatusKey(s.dx_call, s.band ?? '', s.comment ?? '', s.freq_hz);
+      if (seen.has(k)) continue;
+      seen.add(k);
+      queries.push({ call: s.dx_call, band: s.band ?? '', mode: inferSpotMode(s.comment ?? '', s.freq_hz), pota_ref: (s as any).pota_ref ?? '' });
+    }
+    if (!queries.length) return;
+    try {
+      const res = await ClusterSpotStatuses(queries as any);
+      setSpotStatus((prev) => {
+        const next = { ...prev };
+        for (const r of res) {
+          const k = `${r.call}|${r.band ?? ''}|${(r.mode ?? '').toUpperCase()}`;
+          next[k] = {
+            status: r.status ?? '', country: r.country, continent: (r as any).continent,
+            worked_call: !!(r as any).worked_call, new_county: !!(r as any).new_county,
+            new_pota: !!(r as any).new_pota, new_pfx: !!(r as any).new_pfx, pfx: (r as any).pfx,
+          };
+        }
+        return next;
+      });
+    } catch { /* leave the old statuses in place on failure */ }
+  }, []);
+  // After a QSO is logged, refresh the shown spots so a call/entity/POTA/prefix/
+  // slot just worked drops its NEW badge — WITHOUT blanking the others (see the
+  // merge above). Kept cheap: only while the cluster is on screen (a log while
+  // hidden marks it dirty and refreshes ONCE on next open), and debounced so a
+  // fast run coalesces instead of re-scanning per QSO.
   const clusterVisibleRef = useRef(false);
   const spotsDirtyRef = useRef(false);
   useEffect(() => {
     const vis = mainPaneLeft === 'cluster' || mainPaneRight === 'cluster' || activeTab === 'cluster';
     if (vis && !clusterVisibleRef.current && spotsDirtyRef.current) {
       spotsDirtyRef.current = false;
-      setSpotStatus({});
+      void refreshSpotStatuses();
     }
     clusterVisibleRef.current = vis;
-  }, [mainPaneLeft, mainPaneRight, activeTab]);
+  }, [mainPaneLeft, mainPaneRight, activeTab, refreshSpotStatuses]);
   useEffect(() => {
     let t: number | undefined;
     const off = EventsOn('qso:logged', () => {
       if (!clusterVisibleRef.current) { spotsDirtyRef.current = true; return; }
       if (t) window.clearTimeout(t);
-      t = window.setTimeout(() => setSpotStatus({}), 2000);
+      t = window.setTimeout(() => void refreshSpotStatuses(), 2000);
     });
     return () => { off(); if (t) window.clearTimeout(t); };
-  }, []);
+  }, [refreshSpotStatuses]);
   // Incoming spots are staged here for a few ms, their status resolved, then
   // committed to `spots` together — so a row paints with its NEW BAND/MODE badge
   // already on, instead of flashing plain text then flipping to the pill.