fix: sort stock and bond events by payment date

src/shared/lib/calendar.ts

@@ -16,6 +16,12 @@ const moscowFormatter = new Intl.DateTimeFormat("en-CA", {
 	year: "numeric",
 });
 
+// Newest first. Missing dates sort last in both directions, so a row without a
+// date never jumps to the top of a "past" list.
+function compareDateDesc(a: null | string, b: null | string) {
+	return (b ?? "").localeCompare(a ?? "");
+}
+
 function moscowDate(value: Date): string {
 	const parts = moscowFormatter.formatToParts(value);
 
@@ -25,4 +31,4 @@ function moscowDate(value: Date): string {
 	return `${part("year")}-${part("month")}-${part("day")}`;
 }
 
-export { isValidPeriod, moscowDate };
+export { compareDateDesc, isValidPeriod, moscowDate };