feat(viewer): hide link text under QR in share sheet (user request) — QR + copy button remain

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

apps/viewer/src/components/viewer/ShareSheet.vue

@@ -142,7 +142,7 @@ onBeforeUnmount(() => {
           <canvas ref="qrCanvas" width="188" height="188" aria-hidden="true"></canvas>
         </div>
 
-        <p class="share-sheet-url" data-test="share-sheet-url">{{ url }}</p>
+        <!-- 链接文本已按用户要求隐藏（2026-09-24）——二维码 + 复制按钮保留。 -->
 
         <div class="share-sheet-actions">
           <button
@@ -266,14 +266,6 @@ onBeforeUnmount(() => {
   width: 188px;
   height: 188px;
 }
-.share-sheet-url {
-  margin: 0 0 12px;
-  font-size: 0.75rem;
-  color: #647084;
-  word-break: break-all;
-  text-align: center;
-  user-select: text;
-}
 .share-sheet-actions {
   display: flex;
   gap: 10px;