feat(perf): 3-state animation mode (Full / Reduced / Static) (#441)

* feat(perf): 3-state animation mode (Full / Reduced / Static)

Replaces the boolean `reducedAnimations` toggle with a three-way
`animationMode` setting, suggested by Viktor Petrovich after the
Windows audio fix (PR #426) shipped and confirmed a measurable
GPU drop:

- `full` (default): native frame rate, marquee scrolls normally
- `reduced`: 30 fps cap on the animated seekbar wave; player
  marquee runs at half speed
- `static`: rAF loop disabled; the seekbar repaints from the
  ~2 Hz audio:progress heartbeat. Player title/artist truncate
  with ellipsis instead of scrolling.

Migration in `onRehydrateStorage` maps legacy
`reducedAnimations: true` to `'reduced'`, anything else to
`'full'`. Static is opt-in only.

Settings UI follows the ReplayGain Auto/Track/Album pattern with
a contextual hint that explains what each mode does.

i18n: 5 new keys across 8 locales, 2 legacy keys removed.

* docs(changelog): add #441 3-state animation mode entry

* chore(credits): add #441 to Psychotoxical contributions

src/locales/nb.ts

@@ -912,8 +912,13 @@ export const nbTranslation = {
     sidebarLyricsStyleAppleDesc: 'Aktiv linje forankres øverst med jevn animasjon.',
     seekbarStyle: 'Søkefelt-stil',
     seekbarStyleDesc: 'Velg utseendet på avspillingssøkefeltet',
-    reducedAnimations: 'Reduser animasjoner',
-    reducedAnimationsDesc: 'Begrens animerte søkefelt-stiler til 30 fps for å redusere GPU-belastning på tregere maskinvare. Visuell forskjell er minimal.',
+    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',