feat(albums): compilation filter toggle in All Albums

Tri-state button (all / only compilations / hide compilations) in the
Albums page header, using the OpenSubsonic isCompilation tag from
Navidrome. Client-side filter via useMemo, no extra server calls.
Closes #65.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/locales/nl.ts

@@ -289,6 +289,12 @@ export const nlTranslation = {
     yearTo: 'Tot',
     yearFilterClear: 'Jaarfilter wissen',
     yearFilterLabel: 'Jaar',
+    compilationLabel: 'Compilaties',
+    compilationOnly: 'Alleen compilaties',
+    compilationHide: 'Compilaties verbergen',
+    compilationTooltipAll: 'Alle albums · klik: alleen compilaties',
+    compilationTooltipOnly: 'Alleen compilaties · klik: compilaties verbergen',
+    compilationTooltipHide: 'Compilaties verborgen · klik: toon alles',
     select: 'Meervoudige selectie',
     startSelect: 'Meervoudige selectie inschakelen',
     cancelSelect: 'Annuleren',