feat(worked): fold portable callsigns into the worked-before history

Typing RK3DWA found nothing while RK3DWA/3 found 21 QSOs, so a station's
history was only visible if you happened to type the exact form it had been
logged under — and an operator who worked it as /0, /P or /MM saw none of it.
The other RDA tools and Log4OM fold these together; this does too.

The predicate strips the suffix from what was typed and matches "call = base OR
call LIKE base/%", so it works from either end: the base call finds the portable
QSOs and a portable call finds the plain ones. Deliberately not a bare prefix
LIKE 'RK3DWA%', which would also match RK3DWAB — a different station. The '/' is
what makes it the same operator.

Settings -> General to turn it off. Default ON, hence the inverted storage: an
existing install has no key, and reading that as OFF would leave everyone with
the behaviour we were asked to change.

Contest dupe checking is untouched — it runs through ContestDupe, a separate
binding, and stays an exact match as a contest requires.

frontend/src/components/SettingsModal.tsx

@@ -27,6 +27,7 @@ import {
   AudioStartTX, AudioStopTX, AudioTXActive,
   ListClusterServers, SaveClusterServer, DeleteClusterServer,
   GetClusterAutoConnect, SetClusterAutoConnect, GetSelfSpotSettings, SaveSelfSpotSettings,
+  GetWorkedCallVariants, SetWorkedCallVariants,
   ConnectClusterServer, DisconnectClusterServer,
   ConnectAllClusters, DisconnectAllClusters, GetClusterStatus,
   GetBackupSettings, SaveBackupSettings, RunBackupNow, PickBackupFolder,
@@ -1524,6 +1525,8 @@ export function SettingsModal({ onClose, onSaved, initialSection, onMainPaneChan
 
   const [clusterServers, setClusterServers] = useState<ClusterServer[]>([]);
   const [clusterAutoConnect, setClusterAutoConnectState] = useState(false);
+  // Defaults to true so the checkbox matches the backend before the read lands.
+  const [workedVariants, setWorkedVariants] = useState(true);
   // Self-spot. SELF_SPOT_MIN_MIN mirrors the backend floor — the input clamps on
   // blur, not per keystroke, or typing "10" would be rewritten to "5" the moment
   // the "1" landed and the field would fight the operator.
@@ -1632,6 +1635,7 @@ export function SettingsModal({ onClose, onSaved, initialSection, onMainPaneChan
         try { setAudioCfg(await GetAudioSettings() as any); } catch {}
         try { setEmailCfg(await GetEmailSettings() as any); } catch {}
         try { setEqslCfg(await QSLGetEmailTemplates() as any); } catch {}
+        try { setWorkedVariants(await GetWorkedCallVariants()); } catch {}
         reloadAudioDevices();
         reloadDvk();
       } catch (e: any) {
@@ -5666,6 +5670,13 @@ export function SettingsModal({ onClose, onSaved, initialSection, onMainPaneChan
             <Checkbox checked={autofocusWB} onCheckedChange={(c) => { const v = !!c; setAutofocusWB(v); writeUiPref('opslog.autofocusWB', v ? '1' : '0'); }} />
             {t('gen.autofocusWB')}
           </label>
+          {/* Backend setting, not a UI pref: the fold happens in the SQL. Saved
+              instantly like the rest of this panel. */}
+          <label className="flex items-center gap-2 text-sm cursor-pointer">
+            <Checkbox checked={workedVariants}
+              onCheckedChange={(c) => { const v = !!c; setWorkedVariants(v); SetWorkedCallVariants(v).catch((e: any) => setErr(String(e?.message ?? e))); }} />
+            {t('gen.workedVariants')} <span className="text-xs text-muted-foreground">{t('gen.workedVariantsHint')}</span>
+          </label>
           <label className="flex items-center gap-2 text-sm cursor-pointer">
             <Checkbox checked={showBeamMap} onCheckedChange={(c) => { const v = !!c; setShowBeamMap(v); writeUiPref('opslog.showBeamOnMap', v ? '1' : '0'); }} />
             {t('gen.showBeam')}