fix: polish demo-playedu student avatar and login logo.

Replace the cartoon default avatar with a neutral silhouette, remove the login logo white background, and shrink the member avatar size.

demo-playedu/README.md

@@ -9,6 +9,7 @@
 - 管理端、PC、H5 页脚与标题已改
 - 「使用许可」改为「关于本系统」，去掉厂商宣传页
 - 仪表盘产品文档外链已去掉
+- 默认学员头像改为中性人物剪影（替换卡通眨眼脸）
 
 上游协议要求正式交付时保留版权信息；本目录仅为内部演示，正式选型前请再评估协议与改造成本。
 

demo-playedu/playedu/playedu-h5/src/pages/member/index.tsx

@@ -146,10 +146,10 @@ const MemberPage = () => {
                 <Skeleton
                   animated
                   style={{
-                    width: 100,
-                    height: 100,
+                    width: 64,
+                    height: 64,
                     borderRadius: "50%",
-                    marginRight: 20,
+                    marginRight: 14,
                   }}
                 />
                 <div className={styles["other-cont"]}>
@@ -168,11 +168,11 @@ const MemberPage = () => {
               <>
                 {user ? (
                   <Image
-                    width={100}
-                    height={100}
+                    width={64}
+                    height={64}
                     style={{
                       borderRadius: "50%",
-                      marginRight: 20,
+                      marginRight: 14,
                     }}
                     fit="cover"
                     src={