feat(device-sync): overhaul Device Sync page

- New two-panel layout with live album search (search3, 300ms debounce)
  and 10 random albums when search is empty — replaces full paginated load
- Pre-sync summary modal: shows files to add/delete, net change, available
  space; Proceed button disabled when space is insufficient
- calculate_sync_payload now filters already-synced tracks (path exists on
  device) so add_bytes/add_count reflect the true delta
- Space check accounts for pending deletions: addBytes > availableBytes + delBytes
- Separate deviceSyncJobStore for ephemeral job progress state
- Removable drive detection + auto-poll every 5 s via sysinfo
- Desired-state diff: de-selecting a synced source stages it for deletion
  instead of silently removing it
- Status badges (Synced / Pending / Deletion) with matching row highlights
- Live-Search badge (⚡) and Zufallsalben section label (⇌) in album browser
- Status summary row height aligned with search field (52 px)
- i18n: all new keys added to all 8 locales (en/de/fr/nl/nb/zh/ru/es)

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

src/components/Sidebar.tsx

@@ -3,6 +3,7 @@ import { createPortal } from 'react-dom';
 import { usePlayerStore } from '../store/playerStore';
 import { useOfflineStore } from '../store/offlineStore';
 import { useOfflineJobStore } from '../store/offlineJobStore';
+import { useDeviceSyncJobStore } from '../store/deviceSyncJobStore';
 import { useAuthStore } from '../store/authStore';
 import { useSidebarStore } from '../store/sidebarStore';
 import { NavLink } from 'react-router-dom';
@@ -50,6 +51,12 @@ export default function Sidebar({
   const offlineJobs = useOfflineJobStore(s => s.jobs);
   const cancelAllDownloads = useOfflineJobStore(s => s.cancelAllDownloads);
   const activeJobs = offlineJobs.filter(j => j.status === 'queued' || j.status === 'downloading');
+  const syncJobStatus = useDeviceSyncJobStore(s => s.status);
+  const syncJobDone   = useDeviceSyncJobStore(s => s.done);
+  const syncJobSkip   = useDeviceSyncJobStore(s => s.skipped);
+  const syncJobFail   = useDeviceSyncJobStore(s => s.failed);
+  const syncJobTotal  = useDeviceSyncJobStore(s => s.total);
+  const isSyncing     = syncJobStatus === 'running';
   const offlineAlbums = useOfflineStore(s => s.albums);
   const serverId = useAuthStore(s => s.activeServerId ?? '');
   const isLoggedIn = useAuthStore(s => s.isLoggedIn);
@@ -369,6 +376,19 @@ export default function Sidebar({
             </button>
           </div>
         )}
+
+        {isSyncing && (
+          <div
+            className={`sidebar-offline-queue sidebar-sync-queue ${isCollapsed ? 'sidebar-offline-queue--collapsed' : ''}`}
+            data-tooltip={isCollapsed ? t('sidebar.syncingTracks', { done: syncJobDone + syncJobSkip + syncJobFail, total: syncJobTotal }) : undefined}
+            data-tooltip-pos="right"
+          >
+            <HardDriveUpload size={isCollapsed ? 18 : 14} className="spin-slow" />
+            {!isCollapsed && (
+              <span>{t('sidebar.syncingTracks', { done: syncJobDone + syncJobSkip + syncJobFail, total: syncJobTotal })}</span>
+            )}
+          </div>
+        )}
       </nav>
     </aside>
   );