style(portal+login): 7 个 logo 占位符 '医' 换为 logo.png 图片

- components/PortalShell.vue (navbar + footer, 共享给 3 个注册页)
- views/portal/Home.vue (navbar + footer)
- views/portal/ArticleView.vue (navbar + footer)
- views/portal/SpecialPlanDetail.vue (navbar + footer)
- views/portal/Publicity.vue (navbar + footer)
- views/portal/PublicityDetail.vue (navbar + footer)
- views/auth/Login.vue (登录页 logo)

每个 .logo-icon / .footer-logo-icon:
  HTML: <div class='logo-icon'>医</div> → 含 <img src='/logo.png'>
  CSS:  删 background/color/font-size/font-weight (字标样式)
       改 overflow:hidden + object-fit:contain (图片容器)

全站 '医' 字符占位符清零.

ry-vue3/src/views/portal/Publicity.vue

@@ -2,7 +2,7 @@
   <div class="pub-page">
     <header class="top-nav" :class="topNavClass">
       <a class="logo" title="返回首页" @click.prevent="goHome">
-        <div class="logo-icon">医</div>
+        <div class="logo-icon"><img src="/logo.png" alt="logo" /></div>
         <div class="logo-text">
           <span class="logo-title">北京整合医学学会</span>
           <span class="logo-subtitle">Beijing Association of Holistic Integrative Medicine</span>
@@ -81,7 +81,7 @@
         <div class="footer-main">
           <div class="footer-brand">
             <div class="brand-row">
-              <div class="footer-logo-icon">医</div>
+              <div class="footer-logo-icon"><img src="/logo.png" alt="logo" /></div>
               <div>
                 <div class="footer-brand-name">北京整合医学学会</div>
                 <div class="footer-brand-en">Beijing Association of Holistic Integrative Medicine</div>
@@ -309,14 +309,13 @@ a { color: inherit; text-decoration: none; }
 .logo-icon {
     width: 36px;
     height: 36px;
-    background: #fff;
-    color: var(--brand-primary);
     display: flex;
     align-items: center;
     justify-content: center;
-    font-size: 18px;
-    font-weight: 600;
+    overflow: hidden;
+    flex-shrink: 0;
 }
+.logo-icon img { width: 100%; height: 100%; object-fit: contain; display: block; }
 
 .logo-text {
     display: flex;
@@ -617,15 +616,13 @@ a { color: inherit; text-decoration: none; }
 .footer-logo-icon {
     width: 36px;
     height: 36px;
-    background: #fff;
-    color: var(--brand-primary);
     display: flex;
     align-items: center;
     justify-content: center;
-    font-size: 18px;
-    font-weight: 600;
+    overflow: hidden;
     flex-shrink: 0;
 }
+.footer-logo-icon img { width: 100%; height: 100%; object-fit: contain; display: block; }
 
 .footer-brand-name {
     font-size: 16px;