refactor: flatten monorepo into standalone project

src/server/db/index.ts

@@ -0,0 +1,24 @@
+import { drizzle } from 'drizzle-orm/postgres-js'
+import { env } from '@/env'
+import { relations } from '@/server/db/relations'
+
+export const createDB = () =>
+  drizzle({
+    connection: env.DATABASE_URL,
+    relations,
+  })
+
+export type DB = ReturnType<typeof createDB>
+
+export const getDB = (() => {
+  let db: DB | null = null
+
+  return (singleton = true): DB => {
+    if (!singleton) {
+      return createDB()
+    }
+
+    db ??= createDB()
+    return db
+  }
+})()