redesign(project-page): editorial redesign of /works/[slug]

- ProjectHero: full-viewport dark hero with blurred cover image overlay,
  animated entrance (back link → date → title → description), scroll indicator
- ProjectMeta: reveal-animated metadata strip with top/bottom dividers,
  refined label/value typography using brand color tokens
- ProjectTechnologies: outline pill tags with per-tag staggered reveal,
  hover border/color transition
- ProjectsColumns: cleaner 2-col prose grid with wider gap
- ProjectPreviewGrid: rounded-xl with subtle border, responsive 1→2 col
- ProjectVisitButton: pill-shaped dark CTA replacing bordered rectangle
- OtherProjects: image-first card layout with scroll reveal, hover scale +
  brightness on covers, sliding arrow, refined "Voir aussi" header
- page.tsx: passes cover prop to ProjectHero, 900px max-width content
  column, semantic MDX prose styles via article selector chains

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

components/mdx/ProjectsColumns.tsx

@@ -1,11 +1,11 @@
 type props = {
-	children: React.ReactNode;
+    children: React.ReactNode;
 };
 
 export function ProjectsColumns({ children }: props) {
-	return (
-		<div className="grid gap-6 text-justify text-base font-sans lg:grid-cols-2 lg:space-x-6">
-			{children}
-		</div>
-	);
-}
+    return (
+        <div className="grid gap-8 lg:grid-cols-2 lg:gap-14">
+            {children}
+        </div>
+    );
+}