style(settings): trim the DX Cluster panel's explanations

Per review: the digital-grouping sentence on the same-slot option, the
spot-lifetime explanation, the ring-buffer paragraph on the spots-kept field,
and the free-public-nodes line all go.

frontend/src/components/SettingsModal.tsx

@@ -5314,11 +5314,6 @@ function SettingsModalImpl({ onClose, onSaved, initialSection, onMainPaneChanged
               ))}
             </div>
           </div>
-          <p className="text-xs text-muted-foreground">
-            {t('clu.freeNodes')} <span className="font-mono">dxc.k0xm.net:7300</span>,{' '}
-            <span className="font-mono">dx.maritimecontestclub.net:7300</span>,{' '}
-            <span className="font-mono">w8avi.net:7300</span>.
-          </p>
           <label className="flex items-start gap-2 text-sm cursor-pointer border-t border-border/60 pt-3">
             <Checkbox checked={clusterWorkedSameSlot} className="mt-0.5"
               onCheckedChange={(c) => { const v = !!c; setClusterWorkedSameSlot(v); writeUiPref('opslog.clusterWorkedSameSlot', v ? '1' : '0'); }} />
@@ -5380,7 +5375,7 @@ function SettingsModalImpl({ onClose, onSaved, initialSection, onMainPaneChanged
                   const n = parseInt(raw, 10);
                   if (Number.isFinite(n) && n > 0) SetSpotMax(Math.min(10000, n)).catch(() => {});
                 }} />
-              <span className="text-xs text-muted-foreground">{t('clu.spotMaxHint')}</span>
+
             </div>
           </div>