feat(albums): add multi-select to Albums, New Releases, and Random Albums

Select multiple albums to add them to the offline cache or download
each as a separate ZIP. Action buttons appear inline in the topbar
when at least one album is selected; title shows selection count.
AlbumCard gains selectionMode/selected/onToggleSelect props with a
checkmark overlay and selected outline.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/locales/fr.ts

@@ -244,6 +244,17 @@ export const frTranslation = {
     yearTo: 'À',
     yearFilterClear: 'Effacer le filtre année',
     yearFilterLabel: 'Année',
+    select: 'Multi-select',
+    startSelect: 'Enable multi-select',
+    cancelSelect: 'Cancel',
+    selectionCount: '{{count}} selected',
+    downloadZips: 'Download ZIPs',
+    addOffline: 'Add Offline',
+    downloadingZip: 'Downloading {{current}}/{{total}}: {{name}}',
+    downloadZipDone: '{{count}} ZIP(s) downloaded',
+    downloadZipFailed: 'Failed to download {{name}}',
+    offlineQueuing: 'Queuing {{count}} album(s) for offline…',
+    offlineFailed: 'Failed to add {{name}} offline',
   },
   artists: {
     title: 'Artistes',