feat: add real-time TOML validation for Codex config

- Add smol-toml dependency for client-side TOML parsing
- Create useCodexTomlValidation hook with 500ms debounce
- Display validation errors below config.toml textarea
- Trigger validation on onChange for immediate user feedback
- Backend validation remains as fallback for data integrity

src/components/ProviderForm/CodexConfigEditor.tsx

@@ -33,15 +33,17 @@ interface CodexConfigEditorProps {
 
   authError: string;
 
-  isCustomMode?: boolean; // 新增：是否为自定义模式
+  configError: string; // config.toml 错误提示
 
-  onWebsiteUrlChange?: (url: string) => void; // 新增：更新网址回调
+  isCustomMode?: boolean; // 是否为自定义模式
 
-  isTemplateModalOpen?: boolean; // 新增：模态框状态
+  onWebsiteUrlChange?: (url: string) => void; // 更新网址回调
 
-  setIsTemplateModalOpen?: (open: boolean) => void; // 新增：设置模态框状态
+  isTemplateModalOpen?: boolean; // 模态框状态
 
-  onNameChange?: (name: string) => void; // 新增：更新供应商名称回调
+  setIsTemplateModalOpen?: (open: boolean) => void; // 设置模态框状态
+
+  onNameChange?: (name: string) => void; // 更新供应商名称回调
 }
 
 const CodexConfigEditor: React.FC<CodexConfigEditorProps> = ({
@@ -67,6 +69,8 @@ const CodexConfigEditor: React.FC<CodexConfigEditorProps> = ({
 
   authError,
 
+  configError,
+
   onWebsiteUrlChange,
 
   onNameChange,
@@ -324,6 +328,10 @@ const CodexConfigEditor: React.FC<CodexConfigEditorProps> = ({
           data-enable-grammarly="false"
         />
 
+        {configError && (
+          <p className="text-xs text-red-500 dark:text-red-400">{configError}</p>
+        )}
+
         <p className="text-xs text-gray-500 dark:text-gray-400">
           {t("codexConfig.configTomlHint")}
         </p>