refactor(settings): remove redundant Animations 3-state setting (#495)

* refactor(settings): remove redundant Animations 3-state setting under Seekbar Style

The `animationMode` setting (Full / Reduced / Static) duplicated work
the perf-flag system and OS-level reduced-motion preference already
covered:

- `perfFlags.disableMarqueeScroll` already kills marquee scrolling on
  demand, replacing what `static` mode used to gate.
- The `data-perf-disable-animations` html-level switch already strips
  every `*` animation, replacing what `static` mode used to do globally.
- `@media (prefers-reduced-motion: reduce)` honours the OS setting for
  every user that asked for it via system preferences.
- The 30 fps cap that `reduced` mode applied to the seekbar wave was
  better served by per-feature perf toggles cucadmuh added later.

Removed:
- `AnimationMode` type, `animationMode` field + setter from auth store.
- Settings UI block (3 buttons + hint text) under Appearance > Seekbar
  Style.
- `animationMode === 'static'` short-circuit in WaveformSeek's rAF
  effect; `isReduced` skip-every-other-frame logic; `static`-checks in
  `drawNow` / `needsDirectDraw`.
- `animationMode !== 'static'` guard and `data-anim-mode` attribute in
  MarqueeText.
- `[data-anim-mode="static"]` and `[data-anim-mode="reduced"]` rules in
  layout.css.
- Seven i18n keys (animationMode + 6 variants) across all eight
  locales.

Migration: the persist layer strips `animationMode` (and the legacy
`reducedAnimations` boolean predecessor) so anyone who had `'reduced'`
or `'static'` selected silently lands on the former `'full'` path on
first launch after upgrade. No user-facing prompt — the missing setting
just stops existing.

cucadmuh's PR #472 (FPS overlay), #476 (preview-freeze main seekbar,
sleep-recovery hooks, card-hover removal) and #486 (interpolation
anchor reset on resume) are all preserved untouched — they live in
separate effects / files and were not driven by `animationMode`.

* docs(changelog): add Removed section for animationMode setting (PR #495)

* docs(changelog): refine animationMode removal rationale (drop prefers-reduced-motion overstatement)

src/locales/de.ts

@@ -979,13 +979,6 @@ export const deTranslation = {
     sidebarLyricsStyleAppleDesc: 'Aktive Zeile oben mit sanfter Animation.',
     seekbarStyle: 'Seekbar-Stil',
     seekbarStyleDesc: 'Aussehen der Wiedergabe-Seekbar auswählen',
-    animationMode: 'Animationen',
-    animationModeDesc: 'Visuelle Glätte gegen geringere GPU-/CPU-Last auf langsamerer Hardware tauschen.',
-    animationModeFull: 'Voll',
-    animationModeReduced: 'Reduziert',
-    animationModeStatic: 'Statisch',
-    animationModeReducedHint: '30 fps Limit auf der Seekbar-Welle; Titel im Player läuft mit halber Geschwindigkeit.',
-    animationModeStaticHint: 'Keine Wellenanimation; Titel im Player wird abgeschnitten statt gescrollt.',
     seekbarTruewave: 'Echte Wellenform',
     seekbarPseudowave: 'Pseudo-Wellenform',
     seekbarLinedot: 'Linie & Punkt',

src/locales/en.ts

@@ -985,13 +985,6 @@ export const enTranslation = {
     fsPortraitDim: 'Photo dimming',
     seekbarStyle: 'Seekbar Style',
     seekbarStyleDesc: 'Choose the look of the player seek bar',
-    animationMode: 'Animations',
-    animationModeDesc: 'Trade visual smoothness for lower GPU/CPU usage on slower hardware.',
-    animationModeFull: 'Full',
-    animationModeReduced: 'Reduced',
-    animationModeStatic: 'Static',
-    animationModeReducedHint: '30 fps cap on the seekbar wave; player title scrolls at half speed.',
-    animationModeStaticHint: 'No wave animation; player title is truncated instead of scrolling.',
     seekbarTruewave: 'Truewave',
     seekbarPseudowave: 'Pseudowave',
     seekbarLinedot: 'Line & Dot',

src/locales/es.ts

@@ -972,13 +972,6 @@ export const esTranslation = {
     sidebarLyricsStyleAppleDesc: 'La línea activa se ancla arriba con animación suave.',
     seekbarStyle: 'Estilo de Barra de Progreso',
     seekbarStyleDesc: 'Elige la apariencia de la barra de progreso del reproductor',
-    animationMode: 'Animaciones',
-    animationModeDesc: 'Cambia fluidez visual por menor uso de GPU/CPU en hardware más lento.',
-    animationModeFull: 'Completas',
-    animationModeReduced: 'Reducidas',
-    animationModeStatic: 'Estáticas',
-    animationModeReducedHint: 'Límite de 30 fps en la onda de la barra; el título del reproductor se desplaza a la mitad de velocidad.',
-    animationModeStaticHint: 'Sin animación de onda; el título del reproductor se trunca en lugar de desplazarse.',
     seekbarTruewave: 'Forma de Onda Real',
     seekbarPseudowave: 'Forma de Onda Pseudo',
     seekbarLinedot: 'Línea y Punto',

src/locales/fr.ts

@@ -967,13 +967,6 @@ export const frTranslation = {
     sidebarLyricsStyleAppleDesc: "La ligne active reste en haut avec une animation fluide.",
     seekbarStyle: 'Style de la barre de lecture',
     seekbarStyleDesc: 'Choisir l\'apparence de la barre de progression',
-    animationMode: 'Animations',
-    animationModeDesc: 'Échanger la fluidité visuelle contre une utilisation GPU/CPU réduite sur du matériel plus lent.',
-    animationModeFull: 'Complètes',
-    animationModeReduced: 'Réduites',
-    animationModeStatic: 'Statiques',
-    animationModeReducedHint: 'Plafond de 30 fps sur l\'onde de la barre ; le titre du lecteur défile à moitié vitesse.',
-    animationModeStaticHint: 'Pas d\'animation d\'onde ; le titre du lecteur est tronqué au lieu de défiler.',
     seekbarTruewave: 'Forme d\'onde réelle',
     seekbarPseudowave: 'Forme d\'onde pseudo',
     seekbarLinedot: 'Ligne & point',

src/locales/nb.ts

@@ -966,13 +966,6 @@ export const nbTranslation = {
     sidebarLyricsStyleAppleDesc: 'Aktiv linje forankres øverst med jevn animasjon.',
     seekbarStyle: 'Søkefelt-stil',
     seekbarStyleDesc: 'Velg utseendet på avspillingssøkefeltet',
-    animationMode: 'Animasjoner',
-    animationModeDesc: 'Bytt visuell flyt mot lavere GPU-/CPU-bruk på tregere maskinvare.',
-    animationModeFull: 'Full',
-    animationModeReduced: 'Redusert',
-    animationModeStatic: 'Statisk',
-    animationModeReducedHint: '30 fps grense på søkefelt-bølgen; spillertittelen ruller med halv hastighet.',
-    animationModeStaticHint: 'Ingen bølgeanimasjon; spillertittelen forkortes i stedet for å rulle.',
     seekbarTruewave: 'Ekte bølgeform',
     seekbarPseudowave: 'Pseudo-bølgeform',
     seekbarLinedot: 'Linje & punkt',

src/locales/nl.ts

@@ -966,13 +966,6 @@ export const nlTranslation = {
     sidebarLyricsStyleAppleDesc: 'Actieve regel verankerd bovenaan met vloeiende animatie.',
     seekbarStyle: 'Zoekbalkstijl',
     seekbarStyleDesc: 'Kies het uiterlijk van de afspeelbalk',
-    animationMode: 'Animaties',
-    animationModeDesc: 'Wissel visuele soepelheid in voor minder GPU-/CPU-gebruik op tragere hardware.',
-    animationModeFull: 'Volledig',
-    animationModeReduced: 'Gereduceerd',
-    animationModeStatic: 'Statisch',
-    animationModeReducedHint: '30 fps limiet op de zoekbalk-golf; spelertitel scrollt op halve snelheid.',
-    animationModeStaticHint: 'Geen golfanimatie; spelertitel wordt afgekapt in plaats van scrollen.',
     seekbarTruewave: 'Echte golfvorm',
     seekbarPseudowave: 'Pseudo-golfvorm',
     seekbarLinedot: 'Lijn & punt',

src/locales/ru.ts

@@ -1020,13 +1020,6 @@ export const ruTranslation = {
     sidebarLyricsStyleAppleDesc: 'Активная строка фиксируется сверху с плавной анимацией.',
     seekbarStyle: 'Стиль прогресс-бара',
     seekbarStyleDesc: 'Выбор внешнего вида полосы воспроизведения',
-    animationMode: 'Анимации',
-    animationModeDesc: 'Обменивайте визуальную плавность на меньшую нагрузку на GPU/CPU на слабом железе.',
-    animationModeFull: 'Полные',
-    animationModeReduced: 'Сниженные',
-    animationModeStatic: 'Статичные',
-    animationModeReducedHint: 'Ограничение 30 fps для волны прогресс-бара; заголовок плеера прокручивается с половинной скоростью.',
-    animationModeStaticHint: 'Без анимации волны; заголовок плеера обрезается вместо прокрутки.',
     seekbarTruewave: 'Реальная форма волны',
     seekbarPseudowave: 'Псевдо форма волны',
     seekbarLinedot: 'Линия и точка',

src/locales/zh.ts

@@ -961,13 +961,6 @@ export const zhTranslation = {
     sidebarLyricsStyleAppleDesc: '活动行固定在顶部，带有平滑弹簧动画。',
     seekbarStyle: '进度条样式',
     seekbarStyleDesc: '选择播放进度条的外观',
-    animationMode: '动画',
-    animationModeDesc: '在较慢的硬件上以视觉流畅度换取更低的 GPU/CPU 占用。',
-    animationModeFull: '完整',
-    animationModeReduced: '减少',
-    animationModeStatic: '静态',
-    animationModeReducedHint: '进度条波形限制为 30 fps；播放器标题以半速滚动。',
-    animationModeStaticHint: '无波形动画；播放器标题被截断而不滚动。',
     seekbarTruewave: '真实波形',
     seekbarPseudowave: '伪波形',
     seekbarLinedot: '线条与点',