fix(badges): reset border/outline/shadow on worn medal icon

Defensive reset for UC header medal-icon to ensure no wrapping line
from inherited button/link/image styles.

assets/css/routes/user-center/shell.css

@@ -37,6 +37,10 @@ h1.uc-header__name .aksrt-identity-medal {
   vertical-align: middle;
   margin-left: 4px;
   display: inline-block;
+  border: none;
+  outline: none;
+  box-shadow: none;
+  background: transparent;
 }
 
 /* ==================== 页面自有双栏（对齐 zibll .user-center flex，不走全站 float 壳） ==================== */