feat(viewer): remove native share button from share sheet (user request) — copy link only

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

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

@@ -12,7 +12,6 @@
 import { nextTick, onBeforeUnmount, ref, watch } from 'vue';
 import { useI18n } from 'vue-i18n';
 import QRCode from 'qrcode';
-import { canNativeShare } from '../../support/share';
 import { copyText } from '../../support/clipboard';
 
 const props = defineProps<{
@@ -34,7 +33,6 @@ const copyState = ref<'idle' | 'copied' | 'failed'>('idle');
 let copyResetTimer: ReturnType<typeof setTimeout> | undefined;
 let qrAbort: { cancel: () => void } | null = null;
 
-const showNativeShare = canNativeShare();
 
 /** 二维码绘制（url 变化重绘；弹层打开时按可见尺寸绘制）。 */
 async function drawQr(): Promise<void> {
@@ -82,14 +80,6 @@ async function onCopy(): Promise<void> {
   }, 2500);
 }
 
-async function onNativeShare(): Promise<void> {
-  try {
-    await navigator.share({ title: props.title, url: props.url });
-  } catch {
-    // 取消（AbortError）或其他失败：静默——弹层仍在，复制路径可用。
-  }
-}
-
 function onKeydown(event: KeyboardEvent): void {
   if (event.key === 'Escape') {
     event.preventDefault();
@@ -145,15 +135,7 @@ onBeforeUnmount(() => {
         <!-- 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
-            v-if="showNativeShare"
-            type="button"
-            class="share-sheet-btn is-secondary"
-            data-test="share-sheet-native"
-            @click="onNativeShare"
-          >
-            {{ t('viewer.share') }}
-          </button>
+          <!-- 系统分享按钮已按用户要求移除（2026-09-24）——仅保留复制链接。 -->
           <button
             type="button"
             class="share-sheet-btn is-primary"
@@ -289,13 +271,6 @@ onBeforeUnmount(() => {
 .share-sheet-btn.is-primary[data-state='failed'] {
   background: #b54a4a;
 }
-.share-sheet-btn.is-secondary {
-  flex: 0 0 auto;
-  padding: 0 18px;
-  background: #ffffff;
-  border-color: var(--viewer-divider, #d7dfeb);
-  color: var(--viewer-text, #172033);
-}
 .share-sheet-btn:focus-visible {
   outline: 2px solid var(--viewer-primary, #1a73e8);
   outline-offset: 2px;