feat: add registration endpoint

app/api/register/route.ts

@@ -0,0 +1,23 @@
+import prisma from '@prisma/prisma';
+import { NextRequest, NextResponse } from 'next/server';
+
+export async function POST(request: NextRequest) {
+  const { email } = await request.json();
+
+  if (email) {
+    await prisma.user.upsert({
+      create: {
+        email
+      },
+      update: {
+        updatedAt: new Date()
+      },
+      where: {
+        deleted: false,
+        email
+      }
+    });
+  }
+
+  return NextResponse.json({ message: email });
+}