MVP for API Key authentication

src/db/schema/merchant_nonces.ts

@@ -0,0 +1,15 @@
+// db/schema.ts
+import { pgTable, varchar, timestamp, primaryKey } from 'drizzle-orm/pg-core'
+import merchants from './merchants'
+
+export const merchantNonces = pgTable('merchant_nonces', {
+  merchantId: varchar('merchant_id', { length: 64 })
+    .notNull()
+    .references(() => merchants.merchantId, { onDelete: 'cascade' }),
+  nonce: varchar('nonce', { length: 128 }).notNull(),
+  createdAt: timestamp('created_at', { withTimezone: true }).notNull().defaultNow(),
+}, (t) => [
+  primaryKey({ columns: [t.merchantId, t.nonce] }),
+])
+
+export default merchantNonces