fix: add healthcheck endpoint (#671)

apps/web/src/pages/api/health.ts

@@ -0,0 +1,21 @@
+import type { NextApiRequest, NextApiResponse } from 'next';
+
+import { prisma } from '@documenso/prisma';
+
+export default async function handler(_req: NextApiRequest, res: NextApiResponse) {
+  try {
+    await prisma.$queryRaw`SELECT 1`;
+
+    return res.json({
+      status: 'ok',
+      message: 'All systems operational',
+    });
+  } catch (err) {
+    console.error(err);
+
+    return res.status(500).json({
+      status: 'error',
+      message: err.message,
+    });
+  }
+}