feat: check for available updates

frontend/src/components/SettingsModal.tsx

@@ -593,6 +593,7 @@ export function SettingsModal({ onClose, onSaved, initialSection }: Props) {
 
   // General behaviour prefs (mirrored to the DB so they travel with data/).
   const [autofocusWB, setAutofocusWB] = useState(() => localStorage.getItem('opslog.autofocusWB') !== '0');
+  const [checkUpdates, setCheckUpdates] = useState(() => localStorage.getItem('opslog.checkUpdates') !== '0');
   const [showBeamMap, setShowBeamMap] = useState(() => localStorage.getItem('opslog.showBeamOnMap') !== '0');
   const [startEqEnd, setStartEqEnd] = useState(() => localStorage.getItem('opslog.startEqualsEnd') === '1');
   const [lookupOnBlur, setLookupOnBlur] = useState(() => localStorage.getItem('opslog.lookupOnBlur') === '1');
@@ -3285,6 +3286,10 @@ export function SettingsModal({ onClose, onSaved, initialSection }: Props) {
             <Checkbox checked={lookupOnBlur} onCheckedChange={(c) => { const v = !!c; setLookupOnBlur(v); writeUiPref('opslog.lookupOnBlur', v ? '1' : '0'); }} />
             Look up the callsign only after leaving the field <span className="text-xs text-muted-foreground">(not while typing)</span>
           </label>
+          <label className="flex items-center gap-2 text-sm cursor-pointer">
+            <Checkbox checked={checkUpdates} onCheckedChange={(c) => { const v = !!c; setCheckUpdates(v); writeUiPref('opslog.checkUpdates', v ? '1' : '0'); }} />
+            Check for updates at startup <span className="text-xs text-muted-foreground">(notifies when a newer OpsLog is published)</span>
+          </label>
           <TelemetryToggle />
 
           <div className="border-t border-border/60 pt-4 space-y-2">