refactor: tighten OAuth Auth Center copy, layout, and icon

- Trim Auth Center section descriptions to focus on user intent
- Remove duplicate outer heading on the auth settings tab
- Swap Sparkles glyph for CodexIcon on the ChatGPT card
- Generalize codexOauth.authStatus to a neutral "Auth status"
- Register settings.authCenter.* keys across zh/en/ja locales

src/components/providers/forms/CodexOAuthSection.tsx

@@ -89,7 +89,7 @@ export const CodexOAuthSection: React.FC<CodexOAuthSectionProps> = ({
     <div className={`space-y-4 ${className || ""}`}>
       {/* 认证状态标题 */}
       <div className="flex items-center justify-between">
-        <Label>{t("codexOauth.authStatus", "ChatGPT Plus/Pro 认证")}</Label>
+        <Label>{t("codexOauth.authStatus", "认证状态")}</Label>
         <Badge
           variant={hasAnyAccount ? "default" : "secondary"}
           className={hasAnyAccount ? "bg-green-500 hover:bg-green-600" : ""}