feat: add Prisma client singleton

packages/database/src/client.ts

@@ -0,0 +1,12 @@
+import { PrismaClient } from "@prisma/client";
+
+const globalForPrisma = globalThis as unknown as { prisma: PrismaClient };
+
+export const prisma =
+  globalForPrisma.prisma ?? new PrismaClient();
+
+if (process.env.NODE_ENV !== "production") {
+  globalForPrisma.prisma = prisma;
+}
+
+export { PrismaClient } from "@prisma/client";