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/en.ts

@@ -931,8 +931,13 @@ export const enTranslation = {
     fsPortraitDim: 'Photo dimming',
     seekbarStyle: 'Seekbar Style',
     seekbarStyleDesc: 'Choose the look of the player seek bar',
-    reducedAnimations: 'Reduce animations',
-    reducedAnimationsDesc: 'Cap animated seekbar styles to 30 fps to lower GPU usage on slower hardware. Visual difference is minimal.',
+    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',