feat(settings): theme scheduler, UI scale, CustomSelect scroll fix

- Time-based theme scheduler: auto-switches between day/night theme
  based on configurable times; setInterval re-checks every minute
- UI scale slider (80–150%) via CSS zoom on document root; preset
  buttons aligned to actual slider positions
- CustomSelect: scroll listener keeps dropdown anchored on scroll
- All features i18n in 7 languages

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

src/locales/de.ts

@@ -574,6 +574,15 @@ export const deTranslation = {
     seekbarParticletrail: 'Partikel-Spur',
     seekbarLiquidfill: 'Flüssigkeit',
     seekbarRetrotape: 'Retro-Band',
+    themeSchedulerTitle: 'Theme-Zeitplan',
+    themeSchedulerEnable: 'Theme-Zeitplan aktivieren',
+    themeSchedulerEnableSub: 'Wechselt automatisch zwischen zwei Themes basierend auf der Uhrzeit',
+    themeSchedulerDayTheme: 'Tages-Theme',
+    themeSchedulerDayStart: 'Tag beginnt um',
+    themeSchedulerNightTheme: 'Nacht-Theme',
+    themeSchedulerNightStart: 'Nacht beginnt um',
+    uiScaleTitle: 'Interface-Skalierung',
+    uiScaleLabel: 'Zoom',
   },
   changelog: {
     modalTitle: 'Was ist neu',

src/locales/en.ts

@@ -575,6 +575,15 @@ export const enTranslation = {
     seekbarParticletrail: 'Particle Trail',
     seekbarLiquidfill: 'Liquid Fill',
     seekbarRetrotape: 'Retro Tape',
+    themeSchedulerTitle: 'Auto-Switch Theme',
+    themeSchedulerEnable: 'Enable Theme Scheduler',
+    themeSchedulerEnableSub: 'Automatically switch between two themes based on the time of day',
+    themeSchedulerDayTheme: 'Day Theme',
+    themeSchedulerDayStart: 'Day Starts At',
+    themeSchedulerNightTheme: 'Night Theme',
+    themeSchedulerNightStart: 'Night Starts At',
+    uiScaleTitle: 'Interface Scale',
+    uiScaleLabel: 'Zoom',
   },
   changelog: {
     modalTitle: "What's New",

src/locales/fr.ts

@@ -572,6 +572,15 @@ export const frTranslation = {
     seekbarParticletrail: 'Traînée de particules',
     seekbarLiquidfill: 'Tube liquide',
     seekbarRetrotape: 'Bande rétro',
+    themeSchedulerTitle: 'Planificateur de thème',
+    themeSchedulerEnable: 'Activer le planificateur de thème',
+    themeSchedulerEnableSub: 'Bascule automatiquement entre deux thèmes selon l\'heure',
+    themeSchedulerDayTheme: 'Thème de jour',
+    themeSchedulerDayStart: 'Début du jour',
+    themeSchedulerNightTheme: 'Thème de nuit',
+    themeSchedulerNightStart: 'Début de la nuit',
+    uiScaleTitle: "Mise à l'échelle de l'interface",
+    uiScaleLabel: 'Zoom',
   },
   changelog: {
     modalTitle: 'Quoi de neuf',

src/locales/nb.ts

@@ -571,6 +571,15 @@ export const nbTranslation = {
     seekbarParticletrail: 'Partikkelspor',
     seekbarLiquidfill: 'Væskerør',
     seekbarRetrotape: 'Retrotape',
+    themeSchedulerTitle: 'Tidsplanlagt tema',
+    themeSchedulerEnable: 'Aktiver temaplanlegger',
+    themeSchedulerEnableSub: 'Bytter automatisk mellom to temaer basert på tidspunkt',
+    themeSchedulerDayTheme: 'Dagtema',
+    themeSchedulerDayStart: 'Dag starter kl.',
+    themeSchedulerNightTheme: 'Natttema',
+    themeSchedulerNightStart: 'Natt starter kl.',
+    uiScaleTitle: 'Grensesnittskala',
+    uiScaleLabel: 'Zoom',
   },
   changelog: {
     modalTitle: "Nyheter",

src/locales/nl.ts

@@ -572,6 +572,15 @@ export const nlTranslation = {
     seekbarParticletrail: 'Deeltjesspoor',
     seekbarLiquidfill: 'Vloeistofbuis',
     seekbarRetrotape: 'Retrotape',
+    themeSchedulerTitle: 'Thema-planner',
+    themeSchedulerEnable: 'Thema-planner inschakelen',
+    themeSchedulerEnableSub: 'Schakelt automatisch tussen twee thema\'s op basis van de tijd',
+    themeSchedulerDayTheme: 'Dagthema',
+    themeSchedulerDayStart: 'Dag begint om',
+    themeSchedulerNightTheme: 'Nachtthema',
+    themeSchedulerNightStart: 'Nacht begint om',
+    uiScaleTitle: 'Interface schaal',
+    uiScaleLabel: 'Zoom',
   },
   changelog: {
     modalTitle: 'Wat is nieuw',

src/locales/ru.ts

@@ -598,6 +598,15 @@ export const ruTranslation = {
     seekbarParticletrail: 'Частицы',
     seekbarLiquidfill: 'Жидкость',
     seekbarRetrotape: 'Ретро-лента',
+    themeSchedulerTitle: 'Расписание тем',
+    themeSchedulerEnable: 'Включить расписание тем',
+    themeSchedulerEnableSub: 'Автоматически переключается между двумя темами в зависимости от времени суток',
+    themeSchedulerDayTheme: 'Дневная тема',
+    themeSchedulerDayStart: 'День начинается в',
+    themeSchedulerNightTheme: 'Ночная тема',
+    themeSchedulerNightStart: 'Ночь начинается в',
+    uiScaleTitle: 'Масштаб интерфейса',
+    uiScaleLabel: 'Масштаб',
   },
   changelog: {
     modalTitle: 'Что нового',

src/locales/zh.ts

@@ -568,6 +568,15 @@ export const zhTranslation = {
     seekbarParticletrail: '粒子轨迹',
     seekbarLiquidfill: '液体填充',
     seekbarRetrotape: '复古磁带',
+    themeSchedulerTitle: '主题定时切换',
+    themeSchedulerEnable: '启用主题定时器',
+    themeSchedulerEnableSub: '根据一天中的时间自动在两个主题之间切换',
+    themeSchedulerDayTheme: '白天主题',
+    themeSchedulerDayStart: '白天开始时间',
+    themeSchedulerNightTheme: '夜晚主题',
+    themeSchedulerNightStart: '夜晚开始时间',
+    uiScaleTitle: '界面缩放',
+    uiScaleLabel: '缩放',
   },
   changelog: {
     modalTitle: '新功能',