feat: tracklist column reset, device sync cross-platform template fix, filename template builder, privacy policy

- Add "Reset to defaults" button to column picker in AlbumTrackList, PlaylistDetail, Favorites (all 8 locales)
- Fix device sync cross-OS status detection: store filenameTemplate in manifest, use it for path computation on import
- Redesign filename template UI: preset buttons (Standard/Multi-Disc/Alt. Folder), clickable token chips ({artist}, {album}, etc.), clear button
- Fix suggestions section in PlaylistDetail missing album column rendering
- Add PRIVACY.md documenting all third-party integrations (Last.fm, LRCLIB, Apple Music, Discord); link from README

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

src/locales/nl.ts

@@ -153,6 +153,7 @@ export const nlTranslation = {
     trackDuration: 'Duur',
     trackTotal: 'Totaal',
     columns: 'Kolommen',
+    resetColumns: 'Standaard herstellen',
     notFound: 'Album niet gevonden.',
     bioModal: 'Artiest biografie',
     bioClose: 'Sluiten',
@@ -1090,6 +1091,10 @@ export const nlTranslation = {
     actionDelete: 'Verwijderen van apparaat',
     actionApplyAll: 'Alle wijzigingen toepassen',
     templatePreview: 'Voorbeeld',
+    templatePresetStandard: 'Standaard',
+    templatePresetMultiDisc: 'Multi-Disc',
+    templatePresetAltFolder: 'Alt. map',
+    tokenSlashHint: '/ = mapscheidingsteken',
     cancel: 'Annuleren',
     noTargetDir: 'Kies eerst een doelmap.',
     noSources: 'Selecteer minimaal één bron.',