Feat: page Portfolio avec galerie animée, navigation par scroll/touch/clavier

- Composable useScrollNav partagé entre Expertise et Portfolio (wheel/touch/clavier)
- GalleryAnimation : 3 colonnes CSS défilantes infinies avec décalage et delay
- Portfolio : golden grid, mockup centré, infos projet, sidebar vignettes navigables
- API portfolio.json.php alignée sur blueprint project.yml (catchphrase, images_gallery, mockup, keywords, external_links)
- Variable --ease-standard partagée dans variables.css
- Alias @composables ajouté dans vite.config.js
- Refactor Expertise pour utiliser le composable (comportement identique)

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

site/templates/portfolio.json.php

@@ -1,27 +1,23 @@
 <?php
 
 $specificData = [
-  'intro' => [
-    'title' => $page->intro_title()->value(),
-    'text' => $page->intro_text()->value()
-  ],
   'projects' => $page->children()->listed()->map(function($project) {
     return [
-      'title' => $project->title()->value(),
-      'slug' => $project->slug(),
-      'url' => $project->url(),
-      'tagline' => $project->tagline()->value(),
-      'description' => $project->description()->value(),
-      'cover' => $project->cover()->toFile()?->url(),
-      'cover_thumb' => $project->cover()->toFile()?->thumb(['width' => 100])->url(),
-      'gallery' => $project->files()->filterBy('template', 'image')->limit(5)->map(function($img) {
-        return $img->url();
-      })->values(),
-      'impact' => $project->impact()->split(','),
-      'category' => $project->category()->value(),
-      'platforms' => $project->platforms()->split(','),
-      'apple_link' => $project->apple_link()->value(),
-      'android_link' => $project->android_link()->value()
+      'title'          => $project->title()->value(),
+      'slug'           => $project->slug(),
+      'catchphrase'    => $project->catchphrase()->value(),
+      'description'    => $project->description()->value(),
+      'thumbnail'      => $project->thumbnail()->toFile()?->url(),
+      'images_gallery' => $project->images_gallery()->toFiles()->map(fn($f) => $f->url())->values(),
+      'mockup'         => $project->mockup()->toFile()?->url(),
+      'keywords'       => $project->keywords()->toStructure()->map(fn($i) => [
+                            'label' => $i->label()->value(),
+                            'text'  => $i->text()->value(),
+                          ])->values(),
+      'external_links' => $project->external_links()->toStructure()->map(fn($i) => [
+                            'label' => $i->label()->value(),
+                            'url'   => $i->url()->value(),
+                          ])->values(),
     ];
   })->values()
 ];