Add Elysia API scaffold

apps/api/src/db/client.ts

@@ -0,0 +1,13 @@
+import { drizzle } from 'drizzle-orm/postgres-js';
+import postgres from 'postgres';
+import { env } from '../config/env';
+import * as schema from './schema';
+
+export function createDbClient() {
+  if (!env.databaseUrl) {
+    throw new Error('DATABASE_URL is required to create a database client');
+  }
+
+  const client = postgres(env.databaseUrl);
+  return drizzle(client, { schema });
+}