fix(phone-auth): 修复登录加载动画边框样式问题

- 移除登录加载动画中多余的border-white/30样式
- 保证加载动画边框仅显示顶部白色
- 优化登录中加载状态的视觉效果

src/passport/phone-auth/index.tsx

@@ -273,7 +273,7 @@ const PhoneAuthLogin = () => {
           >
             {loading ? (
               <>
-                <div className="w-5 h-5 border-2 border-white/30 border-t-white rounded-full animate-spin" />
+                <div className="w-5 h-5 border-2 border-t-white rounded-full animate-spin" />
                 <span>登录中...</span>
               </>
             ) : (