fix: Added LOTW badge for Lotw users colored depending on their last upload

internal/dxcc/dxcc.go

@@ -339,17 +339,25 @@ func normalizeCallsign(s string) string {
 	// which can change the DXCC entity (HD5MW/8 → HD8MW → Galápagos, not
 	// Ecuador). This is the same class of rule as KG4 and /MM.
 	if areaDigit != 0 {
-		main = replaceFirstDigit(main, areaDigit)
+		main = replaceAreaDigit(main, areaDigit)
 	}
 	return main
 }
 
-// replaceFirstDigit substitutes the first 0-9 digit of a call with d (used to
-// apply a "/N" call-area change). Returns the call unchanged if it has no digit.
-func replaceFirstDigit(call string, d byte) string {
+// replaceAreaDigit substitutes the CALL-AREA digit of a call with d (used to
+// apply a "/N" call-area change). The area digit is the first digit that comes
+// AFTER a prefix letter — NOT a leading digit that is part of a digit-first
+// prefix (7X, 3A, 4X, 9A, 2E…). So 7X2ARA/4 → 7X4ARA (still Algeria, area 4),
+// NOT 4X2ARA (which is Israel — the old first-digit bug). Returns the call
+// unchanged if it has no such digit.
+func replaceAreaDigit(call string, d byte) string {
 	b := []byte(call)
+	seenLetter := false
 	for i := range b {
-		if b[i] >= '0' && b[i] <= '9' {
+		switch {
+		case b[i] >= 'A' && b[i] <= 'Z':
+			seenLetter = true
+		case b[i] >= '0' && b[i] <= '9' && seenLetter:
 			b[i] = d
 			return string(b)
 		}