Add 'apps/mobile/' from commit '5fa30f365f21531094cd4d2045042bb4f1370ac3'

git-subtree-dir: apps/mobile
git-subtree-mainline: 86f8987dff
git-subtree-split: 5fa30f365f

apps/mobile/lib/invoice-number.ts

@@ -0,0 +1,11 @@
+/** Matches web invoice-form default numbering. */
+export function generateInvoiceNumber(): string {
+  const date = new Date().toISOString().slice(0, 10).replace(/-/g, "");
+  return `INV-${date}-${String(Date.now()).slice(-6)}`;
+}
+
+export function defaultDueDate(issueDate: Date): Date {
+  const due = new Date(issueDate);
+  due.setDate(due.getDate() + 30);
+  return due;
+}