chore: Streamline environment configuration and README updates

- Simplify README environment variable section
- Update Vercel configuration to remove API key descriptions
- Prepare for more flexible API key management

README.md

@@ -101,7 +101,7 @@ prompt-optimizer-v3/
 npm install
 
 
-### 配置环境变量
+### 环境变量
 
 1. 在项目根目录创建 `.env.local` 文件
 2. 添加以下配置（也可以在应用内配置）：

vercel.json

@@ -12,11 +12,7 @@
     "silent": true
   },
   "env": {
-    "VITE_GEMINI_API_KEY": {
-      "description": "Gemini API密钥"
-    },
-    "VITE_DEEPSEEK_API_KEY": {
-      "description": "DeepSeek API密钥"
-    }
+    "VITE_GEMINI_API_KEY": "",
+    "VITE_DEEPSEEK_API_KEY": ""
   }
 }