PostgreSQL 데이터 계층 추가

server/repositories/postgres-client.js

@@ -0,0 +1,25 @@
+import postgres from 'postgres'
+
+let client = null
+
+/**
+ * PostgreSQL 클라이언트 조회
+ * @returns {ReturnType<typeof postgres> | null} PostgreSQL 클라이언트
+ */
+export const getPostgresClient = () => {
+  const config = useRuntimeConfig()
+
+  if (!config.databaseUrl) {
+    return null
+  }
+
+  if (!client) {
+    client = postgres(config.databaseUrl, {
+      max: 5,
+      idle_timeout: 20,
+      connect_timeout: 10
+    })
+  }
+
+  return client
+}