feat(themes): Theme Store install counts, downloads & sort (#1036)

* feat(themes): install counts, downloads, popularity & sort in the Theme Store

Each registry theme now carries an install count and a last-changed date. Store
rows show them in a dedicated meta panel (author, popularity bar, total
downloads, last changed), plus a sort dropdown (most popular / newest / name),
zebra-striped rows, a numbered pager, and a note that the stats refresh daily.
Adds a shared formatRelativeTime helper (formatLastSeen now delegates to it).

* test(themes): cover sort modes, pager jump and relative-time formatting

* fix(build): gate nvidia_quirk_active to Linux

Its only caller is the Linux branch of theme_animation_risk, so on Windows and
macOS the function was dead code and tripped clippy's -D warnings.

* docs: CHANGELOG + credits for theme store download stats & sort (#1036)

src/locales/nl/settings.ts

@@ -325,6 +325,7 @@ export const settings = {
   themeStoreSubmitText: 'Eigen thema gemaakt? Deel het met de community — meer info in de themarepository.',
   themeStoreSubmitLink: 'Themarepository openen',
   themeStoreNetworkNotice: 'De Theme Store laadt de catalogus en previews van externe diensten (de jsDelivr-CDN en GitHub). Er worden geen persoonlijke gegevens verzonden.',
+  themeStoreStatsNotice: 'Download- en laatst-gewijzigd-statistieken worden eenmaal per dag bijgewerkt (rond 04:17 UTC).',
   themeStoreSearchPlaceholder: "Thema's zoeken…",
   themeStoreFilterMode: 'Filteren op modus',
   themeStoreModeAll: 'Alle',
@@ -338,7 +339,13 @@ export const settings = {
   themeStoreEmpty: "Geen thema's komen overeen met je filters.",
   themeStoreActive: 'Actief',
   themeStoreEnlarge: 'Voorbeeld vergroten',
-  themeStoreByAuthor: 'door {{author}}',
+  themeStoreSortPopular: 'Populairste',
+  themeStoreSortNewest: 'Nieuwste',
+  themeStoreSortName: 'Alfabetisch',
+  themeStoreAuthor: 'Auteur',
+  themeStorePopularity: 'Populariteit',
+  themeStoreDownloads: 'Totaal downloads',
+  themeStoreLastChanged: 'Laatst gewijzigd',
   themeMigrationNoticeTitle: 'Thema verplaatst naar de store',
   themeMigrationNoticeBody: '{{themes}} wordt niet meer met de app meegeleverd. Je kunt het opnieuw installeren via de Theme Store (Instellingen → Thema\'s) of een ander thema kiezen.',
   themeMigrationNoticeOpen: 'Theme Store openen',