Refactor: snake_case → camelCase dans blueprints, templates et vues

- Blueprints : renommage des champs (member_name, related_articles,
  background_video, play_links, images_gallery, external_links) et
  des noms de sections
- Templates JSON PHP : clés de sortie et appels ->method() en camelCase
- Vues Svelte (Play, Portfolio) : accès aux données alignés

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

site/templates/blog.json.php

@@ -2,8 +2,8 @@
 
 $specificData = [
   'intro' => [
-    'title' => $page->intro_title()->value(),
-    'text' => $page->intro_text()->value()
+    'title' => $page->introTitle()->value(),
+    'text' => $page->introText()->value()
   ],
   'articles' => $page->children()->listed()->sortBy('date', 'desc')->map(function($article) {
     return [
@@ -11,11 +11,11 @@ $specificData = [
       'slug' => $article->slug(),
       'url' => $article->url(),
       'date' => $article->date()->toDate('Y-m-d'),
-      'date_formatted' => $article->date()->toDate('d/m/Y'),
+      'dateFormatted' => $article->date()->toDate('d/m/Y'),
       'intro' => $article->intro()->excerpt(200),
       'cover' => $article->cover()->toFile()?->url(),
-      'author_name' => $article->author_name()->value(),
-      'author_photo' => $article->author_photo()->toFile()?->url()
+      'authorName' => $article->authorName()->value(),
+      'authorPhoto' => $article->authorPhoto()->toFile()?->url()
     ];
   })->values()
 ];