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>

src/views/Portfolio.svelte

@@ -13,7 +13,7 @@
   // --- Derived ---
   const isActive          = $derived(slides.active?.id === 'portfolio')
   const projects          = $derived(data?.projects ?? [])
-  const backgroundImage   = $derived(data?.background_image ?? null)
+  const backgroundImage   = $derived(data?.backgroundImage ?? null)
   const currentProject = $derived(projects[currentIndex] ?? null)
 
   // Capture du hash synchrone avant que tout effect puisse le modifier
@@ -96,7 +96,7 @@
   {#if currentProject}
     <!-- Galerie animation (gauche) -->
     <div class="portfolio-gallery" aria-hidden="true">
-      <GalleryAnimation images={currentProject.images_gallery} backgroundColor={currentProject.gallery_background_color} />
+      <GalleryAnimation images={currentProject.imagesGallery} backgroundColor={currentProject.galleryBackgroundColor} />
     </div>
 
     <!-- Mockup device (centre) -->
@@ -107,7 +107,7 @@
     <!-- Infos projet (droite) -->
     <div class="portfolio-text" aria-live="polite">
       <h2>{currentProject.title}</h2>
-      <h3 class="portfolio-catchphrase gradient-blue">{@html currentProject.catchphrase}</h3>
+      <h3 class="portfolio-catchphrase gradient-blue">{@html currentProject.catchPhrase}</h3>
       <div class="portfolio-description">{@html currentProject.description}</div>
       <div class="portfolio-keywords">
         {#each currentProject.keywords as kw}
@@ -115,7 +115,7 @@
         {/each}
       </div>
       <div class="portfolio-links">
-        {#each currentProject.external_links as link}
+        {#each currentProject.externalLinks as link}
           <a href={link.url} target="_blank" rel="noopener noreferrer" class="button earth-icon">{link.label}</a>
         {/each}
       </div>