完善serverless部署环境

server/db-schema-check.js

@@ -4,8 +4,15 @@
  */
 require('dotenv').config();
 const db = require('./db');
-const path = require('path');
-const fs = require('fs');
+
+const IS_SERVERLESS = [
+  process.env.SERVERLESS,
+  process.env.VERCEL,
+  process.env.AWS_LAMBDA_FUNCTION_NAME,
+  process.env.NETLIFY,
+  process.env.FUNCTION_TARGET,
+  process.env.K_SERVICE
+].some(Boolean);
 
 const SCHEMA = {
   users: {
@@ -210,8 +217,14 @@ async function ensureTable(tableName, tableSchema) {
 }
 
 async function checkAndFixDatabase() {
-  const envPath = path.join(__dirname, '..', '.env');
-  if (!fs.existsSync(envPath)) return;
+  const autoSchemaSync = process.env.DB_AUTO_SCHEMA_SYNC
+    ? process.env.DB_AUTO_SCHEMA_SYNC === 'true'
+    : !IS_SERVERLESS;
+  const hasDbConfig = Boolean(process.env.MYSQL_HOST && process.env.MYSQL_USER && process.env.MYSQL_DATABASE);
+
+  if (!hasDbConfig || !autoSchemaSync) {
+    return;
+  }
 
   try {
     for (const [tableName, tableSchema] of Object.entries(SCHEMA)) {