fix(i18n): restore reducedAnimations + statistics.export* strings dropped by #419 squash (#433)

* fix(i18n): restore reducedAnimations locale strings dropped by #419 squash

The 'Reduce animations' toggle introduced in PR #426 ships with two
i18n keys (settings.reducedAnimations + settings.reducedAnimationsDesc).
The #419 squash-merge silently removed them from all 8 locales, and
the #429 restore took the locale files from HEAD instead of merging
them, so the keys never came back. The toggle was rendering as raw
keys in the UI.

Restoring the strings to the 5662dafe state for all 8 supported
languages (en, de, fr, nl, zh, nb, ru, es).

* fix(i18n): restore statistics.export* locale strings dropped by #419 squash

Same root cause as the previous commit on this branch: the #419
squash-merge silently dropped 18 statistics.export* keys (introduced
by the Stats-Card-Export PR #425) from en.ts and de.ts. Stats →
"Share Top Albums" modal and the export button tooltip showed raw
keys.

Restoring all 18 keys verbatim from the 5662dafe state in en + de.

Note: PR #425 only ever shipped en + de translations for these keys —
the other 6 locales (fr, nl, zh, nb, ru, es) never had them and are
not in scope for this restore. i18next falls back to en for those, so
users on those languages see the English strings rather than raw keys.
A follow-up to fully translate the export modal across the remaining
locales is tracked separately.

src/locales/zh.ts

@@ -897,6 +897,8 @@ 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',
+    reducedAnimations: '减少动画',
+    reducedAnimationsDesc: '将动画进度条样式限制为 30 fps，以降低较慢硬件上的 GPU 占用。视觉差异极小。',
     seekbarTruewave: '真实波形',
     seekbarPseudowave: '伪波形',
     seekbarLinedot: '线条与点',