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-tauri/Cargo.toml

@@ -45,6 +45,7 @@ discord-rich-presence = "0.2"
 url = "2"
 thread-priority = "1"
 lofty = "0.22"
+sysinfo = { version = "0.33", default-features = false, features = ["disk"] }
 id3 = "1.16.4"
 
 [target.'cfg(unix)'.dependencies]