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.

app.go

@@ -293,6 +293,12 @@ const (
 
 	keyScpEnabled = "scp.enabled" // Super Check Partial / N+1 suggestions on
 
+	// Worked-before: fold an operator's portable forms (X, X/3, X/P) together.
+	// Stored inverted — "0" means OFF — so the feature is ON for an existing
+	// install that has never seen the key, which is the behaviour operators asked
+	// for. See GetWorkedCallVariants.
+	keyWorkedCallVariants = "worked.call_variants"
+
 	keyBackupEnabled   = "backup.enabled"
 	keyBackupFolder    = "backup.folder"
 	keyBackupRotation  = "backup.rotation"
@@ -6091,6 +6097,31 @@ func (a *App) bulkSetFrequency(ids []int64, value string) (int64, error) {
 	return n, nil
 }
 
+// GetWorkedCallVariants reports whether "worked before" folds an operator's
+// portable forms together (RK3DWA ↔ RK3DWA/3 ↔ RK3DWA/P).
+//
+// Defaults to ON, hence the inverted storage: an install that predates the
+// setting has no key at all, and reading that as OFF would leave every existing
+// operator with the old narrow behaviour they asked us to change.
+func (a *App) GetWorkedCallVariants() (bool, error) {
+	if a.settings == nil {
+		return true, fmt.Errorf("db not initialized")
+	}
+	v, err := a.settings.Get(a.ctx, keyWorkedCallVariants)
+	if err != nil {
+		return true, err
+	}
+	return v != "0", nil
+}
+
+// SetWorkedCallVariants persists the toggle.
+func (a *App) SetWorkedCallVariants(on bool) error {
+	if a.settings == nil {
+		return fmt.Errorf("db not initialized")
+	}
+	return a.settings.Set(a.ctx, keyWorkedCallVariants, boolStr(on))
+}
+
 // WorkedBefore returns prior contacts with the given callsign at both
 // call and DXCC granularity. Pass dxccHint=0 when unknown — the function
 // will infer it from past QSOs with the same call when possible.
@@ -6107,7 +6138,8 @@ func (a *App) WorkedBefore(callsign string, dxccHint int) (qso.WorkedBefore, err
 			dxccHint = dxcc.EntityDXCC(m.Entity.Name)
 		}
 	}
-	wb, err := a.qso.WorkedBefore(a.ctx, callsign, dxccHint)
+	variants, _ := a.GetWorkedCallVariants()
+	wb, err := a.qso.WorkedBefore(a.ctx, callsign, dxccHint, variants)
 	// Attach the ClubLog Most Wanted rank for this entity (opt-in) so the entry
 	// matrix can show it next to the country name.
 	if err == nil && wb.DXCC > 0 && a.clublogMW != nil && a.clublogMostWantedEnabled() {