feat(themes): fresher store refresh + external-services notice (#1016)

* feat(themes): fresher store refresh + external-services notice

Manual refresh now fetches the registry from GitHub raw first (~5 min
cache) and falls back to the jsDelivr CDN, so a freshly merged theme shows
up without waiting on — or purging — the shared CDN @main edge (up to
12 h). Normal loads still use the CDN.

Adds a notice on the Theme Store that the catalogue and previews load from
external services (jsDelivr / GitHub), in line with the app's network
transparency. i18n ×9.

* docs(themes): note the store-refresh PR in the Theme Store entry

Now that #1015 is merged, fold PR #1016 into the still-unreleased Theme
Store changelog and credits entry.

src/locales/nb/settings.ts

@@ -326,6 +326,7 @@ export const settings = {
   themeStoreTitle: 'Temabutikk',
   themeStoreSubmitText: 'Laget ditt eget tema? Del det med fellesskapet — mer info i tema-repoet.',
   themeStoreSubmitLink: 'Åpne tema-repoet',
+  themeStoreNetworkNotice: 'Theme Store laster katalogen og forhåndsvisninger fra eksterne tjenester (jsDelivr-CDN og GitHub). Ingen personopplysninger sendes.',
   themeStoreSearchPlaceholder: 'Søk i temaer…',
   themeStoreFilterMode: 'Filtrer etter modus',
   themeStoreModeAll: 'Alle',