Fix/Feat: footer, newsletter, logo footerLogo, i18n, router formatting

- Footer : newsletter commentée, margin-top blog, text-align footer-col
- Blueprint site : logo → footerLogo (champ dédié au pied de page)
- Controller : logo → footerLogo
- i18n : newsletter_heading mis à jour (newsletters)
- site.svelte.js : retrait console.log debug
- router/index.js : reformatage quotes (linter)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

site/controllers/site.php

@@ -16,7 +16,7 @@ return function ($page, $kirby, $site) {
     'site' => [
       'title' => $site->siteTitle()->value(),
       'url' => $site->url(),
-      'logo' => $site->logo()->toFile()?->url(),
+      'logo' => $site->footerLogo()->toFile()?->url(),
       'language' => $kirby->language()?->code() ?? 'fr',
       'languages' => $kirby->languages()->map(function($l) {
         return [