fix(viewer): replace text arrow share icon with SVG share glyph

Co-Authored-By: Claude Code <noreply@anthropic.com>

apps/viewer/src/components/album/AlbumHeader.vue

@@ -184,9 +184,14 @@ onBeforeUnmount(() => {
     <header class="album-info">
       <div class="title-row">
         <h1 ref="titleEl" class="title" :class="{ clamped: !titleExpanded }">{{ album.translation.title }}</h1>
-        <!-- 参考稿：44px 主色圆钮 + 白 ↗ 图标（文案由 aria-label 承载） -->
+        <!-- 44px 主色圆钮 + 白色 SVG 分享图标（aria-label 承载文案） -->
         <button type="button" class="share-btn" :aria-label="t('viewer.shareAlbum')" @click="share">
-          <span class="share-icon" aria-hidden="true">↗</span>
+          <svg class="share-icon" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true">
+            <circle cx="18" cy="5" r="3.2"/>
+            <circle cx="6" cy="12" r="3.2"/>
+            <circle cx="18" cy="19" r="3.2"/>
+            <path d="m8.6 13.5 6.8 4M15.4 6.5l-6.8 4"/>
+          </svg>
         </button>
       </div>
       <button v-if="titleClamped" type="button" class="text-expand" @click="titleExpanded = !titleExpanded">
@@ -327,7 +332,7 @@ onBeforeUnmount(() => {
   -webkit-line-clamp: 2;
   overflow: hidden;
 }
-/* 参考稿：44px 主色圆形分享钮（白 ↗，无边框） */
+/* 44px 主色圆形分享钮（白色 SVG 分享图标） */
 .share-btn {
   flex: none;
   display: inline-flex;
@@ -348,10 +353,9 @@ onBeforeUnmount(() => {
   filter: brightness(0.94);
 }
 .share-icon {
-  font-size: 1.25rem;
-  line-height: 1;
-  /* 视觉基线微调：↗ 略下沉 */
-  transform: translateY(-1px);
+  width: 20px;
+  height: 20px;
+}
 }
 .share-btn:focus-visible {
   outline: 2px solid var(--viewer-primary, #1a73e8);