feat(viewer): UI-02 heart particles, interaction notices, share and download

Task 5 (V05 §5.4/§6): decorative heart particles on the lightbox stage
(local like clicks + others' WS bursts for the current photo), compact
cross-photo interaction notices above the action bar (click to locate),
navigator.share-first share orchestration with clipboard fallback for
album and photo deep links (lang param), and download failures attributed
to the photo that triggered them. Self-echo dedup stays in the realtime
router (own batches never produce particles/notices); particles cap at
12 with visibility/unmount cleanup and are suppressed under reduced
motion; notices cap at 3 with ~4s auto-dismiss and throttled SR summary.

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

apps/viewer/src/i18n/locales/en.ts

@@ -90,6 +90,10 @@ export default {
     more: 'More options',
     thumbnails: 'Thumbnail navigation',
     thumbItem: 'Photo {n}',
+    // —— UI-02 (V05 interaction particles / share) additions ——
+    photoLiked: '+{delta}',
+    sharePhoto: 'Share photo',
+    shareAlbum: 'Share album',
   },
   route: { tokenLabel: 'Album token', photoLabel: 'Photo' },
   errors: {

apps/viewer/src/i18n/locales/zh-CN.ts

@@ -90,6 +90,10 @@ export default {
     more: '更多选项',
     thumbnails: '缩略图导航',
     thumbItem: '第 {n} 张',
+    // —— UI-02（V05 互动粒子/分享）新增 ——
+    photoLiked: '+{delta}',
+    sharePhoto: '分享照片',
+    shareAlbum: '分享相册',
   },
   route: { tokenLabel: '相册令牌', photoLabel: '照片' },
   errors: {