feat: updated format number helper (#719)

Author: frano-m

app/viewModelBuilders/catalog/brc-analytics-catalog/common/viewModelBuilders.ts

@@ -1057,8 +1057,9 @@ function getPriorityPathogenEntityBreadcrumbs(
 /**
  * Format a number to a string.
  * @param value - Number to format.
- * @returns Formatted number.
+ * @returns Formatted number or empty string if invalid.
  */
-export function formatNumber(value: number | null): string {
-  return value?.toLocaleString() || "";
+export function formatNumber(value: unknown): string {
+  if (typeof value !== "number" || Number.isNaN(value)) return "";
+  return value.toLocaleString();
 }