feat: change email template + add list of items

apps/api/prisma/migrations/20261009120000_tab_snapshot_items/migration.sql

@@ -0,0 +1,2 @@
+-- AlterTable
+ALTER TABLE "OpenTabSnapshot" ADD COLUMN     "items" JSONB;

apps/api/prisma/schema.prisma

@@ -77,6 +77,9 @@ model OpenTabSnapshot {
   version      Int
   totalInCents Int
   itemCount    Int
+  // The tab's lines as reported by the terminal: [{ productName, quantity, unitPriceInCents }].
+  // Null for terminals running an app version that doesn't report them.
+  items        Json?
   reportedAt   DateTime
 
   device Device @relation(fields: [deviceId], references: [id])