feat(themes): warn about animated themes on high-CPU setups (#1020)

* feat(themes): warn about animated themes on high-CPU setups

Show a warning icon + tooltip on animated themes (those defining
@keyframes) in the store and in Your Themes, on Linux setups where
animation is costly — the Nvidia WebKit quirk is active or compositing
is forced off. The Nvidia detection already runs once at startup; its
result is recorded (theme_animation.rs) and read via a new
theme_animation_risk command — no GPU re-probe. Display-only; never
shown off Linux. The animated flag comes from the registry (store) or
the theme CSS (Your Themes).

* docs(themes): note the animated-theme warning PR in the Theme Store entry

src/locales/nl/settings.ts

@@ -320,6 +320,7 @@ export const settings = {
   tabThemes: "Thema's",
   themesYourThemesTitle: "Jouw thema's",
   themesCvdTooltip: 'Kleurenblind-veilig – deuteranopie, protanopie, tritanopie',
+  themeAnimationWarning: 'Dit thema gebruikt animaties die het CPU-gebruik op jouw systeem kunnen verhogen (Nvidia/Linux of compositing uit).',
   themeStoreTitle: 'Themawinkel',
   themeStoreSubmitText: 'Eigen thema gemaakt? Deel het met de community — meer info in de themarepository.',
   themeStoreSubmitLink: 'Themarepository openen',