feat(home): add Discover Songs rail to Mainstage (#301)

Reuses the SongRail component from the Tracks hub — 18 random songs
fetched in parallel with the other Home queries. No reroll button.
Click-to-play uses enqueueAndPlay so the existing queue stays intact.

New homeStore section id 'discoverSongs' inserted after 'discover'
in DEFAULT_HOME_SECTIONS. onRehydrateStorage now appends any newly
introduced sections to a previously persisted layout — existing users
get the rail without a manual Reset. Settings → Personalisation
Home-Customizer surfaces it automatically via SECTION_LABELS.

i18n key home.discoverSongs added to all 8 locales.

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

src/locales/de.ts

@@ -41,6 +41,7 @@ export const deTranslation = {
     mostPlayed: 'Meistgehört',
     recentlyPlayed: 'Kürzlich gespielt',
     discover: 'Entdecken',
+    discoverSongs: 'Titel entdecken',
     loadMore: 'Mehr laden',
     discoverMore: 'Mehr entdecken',
     discoverArtists: 'Künstler entdecken',

src/locales/en.ts

@@ -43,6 +43,7 @@ export const enTranslation = {
     mostPlayed: 'Most Played',
     recentlyPlayed: 'Recently Played',
     discover: 'Discover',
+    discoverSongs: 'Discover Songs',
     loadMore: 'Load More',
     discoverMore: 'Discover More',
     discoverArtists: 'Discover Artists',

src/locales/es.ts

@@ -42,6 +42,7 @@ export const esTranslation = {
     mostPlayed: 'Más Reproducidos',
     recentlyPlayed: 'Reproducidos Recientemente',
     discover: 'Descubrir',
+    discoverSongs: 'Descubrir canciones',
     loadMore: 'Cargar Más',
     discoverMore: 'Descubrir Más',
     discoverArtists: 'Descubrir Artistas',

src/locales/fr.ts

@@ -41,6 +41,7 @@ export const frTranslation = {
     mostPlayed: 'Les plus écoutés',
     recentlyPlayed: 'Récemment écoutés',
     discover: 'Découvrir',
+    discoverSongs: 'Découvrir des titres',
     loadMore: 'Charger plus',
     discoverMore: 'Découvrir plus',
     discoverArtists: 'Découvrir des artistes',

src/locales/nb.ts

@@ -41,6 +41,7 @@ export const nbTranslation = {
     mostPlayed: 'Mest spilt',
     recentlyPlayed: 'Nylig spilt',
     discover: 'Oppdag',
+    discoverSongs: 'Oppdag spor',
     loadMore: 'Last inn flere',
     discoverMore: 'Oppdag flere',
     discoverArtists: 'Oppdag artister',

src/locales/nl.ts

@@ -41,6 +41,7 @@ export const nlTranslation = {
     mostPlayed: 'Meest gespeeld',
     recentlyPlayed: 'Recent afgespeeld',
     discover: 'Ontdekken',
+    discoverSongs: 'Nummers ontdekken',
     loadMore: 'Meer laden',
     discoverMore: 'Meer ontdekken',
     discoverArtists: 'Artiesten ontdekken',

src/locales/ru.ts

@@ -43,6 +43,7 @@ export const ruTranslation = {
     mostPlayed: 'Популярное',
     recentlyPlayed: 'Недавно проиграно',
     discover: 'Обзор',
+    discoverSongs: 'Открыть треки',
     loadMore: 'Ещё',
     discoverMore: 'Смотреть ещё',
     discoverArtists: 'Исполнители',

src/locales/zh.ts

@@ -41,6 +41,7 @@ export const zhTranslation = {
     mostPlayed: '最常播放',
     recentlyPlayed: '最近播放',
     discover: '发现',
+    discoverSongs: '发现曲目',
     loadMore: '加载更多',
     discoverMore: '发现更多',
     discoverArtists: '发现艺术家',