feat: QSO rate meter (10/60 min) in the header

Opt-in via Settings→General (portable pref opslog.showQsoRate). Shows the
contest-style QSO rate in QSOs/hour, projected from the trailing 10-minute
(count ×6) and 60-minute windows, between the widget icons and propagation.

Backend: qso.RecentRate counts QSOs whose start time falls in each trailing
window, scanning only the last 400 rows (cheap on a large log); App.GetQSORate
exposes the 10/60-min counts. Frontend refreshes on qso:logged and a 30s tick.

The meter shares the propagation grid cell — the header is a fixed 6-column
grid, so adding it as its own child pushed profile/band-map/compact onto a
second row. i18n EN + FR.

frontend/src/App.tsx

@@ -1,6 +1,6 @@
 import { useCallback, useEffect, useMemo, useRef, useState } from 'react';
 import {
-  AlertCircle, Antenna, Bell, CheckCircle2, Clock, CloudOff, Compass, Database, Ear, Eraser, Hash, Loader2, Lock,
+  Activity, AlertCircle, Antenna, Bell, CheckCircle2, Clock, CloudOff, Compass, Database, Ear, Eraser, Hash, Loader2, Lock,
   Maximize2, Minimize2, Mic, MessageSquare, Pencil, RadioTower, RefreshCw, Satellite, Send, Settings, SlidersHorizontal, Square, Terminal, Trash2, Unlock, X, Zap,
 } from 'lucide-react';
 
@@ -28,6 +28,7 @@ import {
   ListClusterServers, ClusterSpotStatuses, SendClusterSpot,
   GetCATSettings,
   GetSolarData,
+  GetQSORate,
   LoTWUserInfo,
   OperatingDefaultForBand,
   LogUDPLoggedADIF,
@@ -1085,6 +1086,20 @@ export default function App() {
   const [showSettings, setShowSettings] = useState(false);
   // Re-read the "beam on map" toggle when Preferences closes (it's edited there).
   useEffect(() => { if (!showSettings) setShowBeamOnMap(localStorage.getItem('opslog.showBeamOnMap') !== '0'); }, [showSettings]);
+  // QSO-rate meter (10/60 min) in the header — opt-in via Settings→General.
+  const [showQsoRate, setShowQsoRate] = useState(() => localStorage.getItem('opslog.showQsoRate') === '1');
+  useEffect(() => { if (!showSettings) setShowQsoRate(localStorage.getItem('opslog.showQsoRate') === '1'); }, [showSettings]);
+  const [qsoRate, setQsoRate] = useState<{ last10: number; last60: number }>({ last10: 0, last60: 0 });
+  useEffect(() => {
+    if (!showQsoRate) return;
+    const load = () => { GetQSORate().then((r) => setQsoRate({ last10: r?.last10 ?? 0, last60: r?.last60 ?? 0 })).catch(() => {}); };
+    load();
+    // Refresh on each logged QSO (immediate feedback) and on a 30s tick so the
+    // trailing windows roll forward even when nothing new is logged.
+    const off = EventsOn('qso:logged', load);
+    const id = window.setInterval(load, 30 * 1000);
+    return () => { off(); window.clearInterval(id); };
+  }, [showQsoRate]);
   // Optional deep-link: which Preferences section to open. Cleared on
   // close so the next plain "Preferences" launch reverts to default.
   const [settingsSection, setSettingsSection] = useState<string | undefined>(undefined);
@@ -3738,6 +3753,28 @@ export default function App() {
             )}
           </div>
 
+          {/* QSO-rate meter (opt-in) + propagation share ONE grid cell: the header
+              is a fixed 6-column grid, so adding the meter as its own child pushed
+              the last columns (profile / band map / compact) onto a 2nd row. */}
+          <div className="flex items-center gap-2">
+          {showQsoRate && (
+            <div className="flex items-center gap-2.5 font-mono px-2.5 h-8 rounded-md border border-border/60 bg-muted/40 whitespace-nowrap"
+              title={t('rate.title')}>
+              <Activity className="size-3.5 text-muted-foreground" />
+              {/* Contest-style rate: QSOs/hour projected from each window
+                  (10-min count ×6; the 60-min count is already per hour). */}
+              <span className="inline-flex items-baseline gap-1">
+                <span className="text-muted-foreground uppercase tracking-wider text-[9px]">10′</span>
+                <span className="font-bold text-[12px] text-foreground">{qsoRate.last10 * 6}</span>
+              </span>
+              <span className="inline-flex items-baseline gap-1">
+                <span className="text-muted-foreground uppercase tracking-wider text-[9px]">60′</span>
+                <span className="font-bold text-[12px] text-foreground">{qsoRate.last60}</span>
+              </span>
+              <span className="text-muted-foreground text-[9px] uppercase tracking-wider">Q/h</span>
+            </div>
+          )}
+
           {/* Space-weather / propagation — compact, in the header. Live from N0NBH
               (hamqsl.com), auto-refreshed hourly; the same SFI / A / K are stamped
               onto each logged QSO. Always renders one element so the grid columns
@@ -3765,6 +3802,7 @@ export default function App() {
               })()}
             </div>
           ) : <span />}
+          </div>
 
           <div className="flex items-center gap-1.5 font-mono text-xs text-muted-foreground px-2.5 py-1 bg-muted rounded-md border border-border/60">
             <Clock className="size-3" />