✨ Add project detail page with prev/next navigation (Story 2.3)

- Enhance ProjectController show() with prev/next navigation data
- Create useFetchProject composable with ProjectNavigation type
- Implement [slug].vue with full project details:
  - Hero image, title with featured badge, formatted date
  - Description, external links (site/GitHub)
  - Skills grid with level progression (before → after)
  - Prev/next navigation with project titles
  - 404 state with spider narrator
- Add dynamic SEO meta tags with og:image from project
- Responsive design: stacked mobile, grid desktop

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docs/implementation-artifacts/sprint-status.yaml

@@ -58,8 +58,8 @@ development_status:
   # ═══════════════════════════════════════════════════════════════════════════
   epic-2: in-progress
   2-1-composant-projectcard: review
-  2-2-page-projets-galerie: ready-for-dev
-  2-3-page-projet-detail: ready-for-dev
+  2-2-page-projets-galerie: review
+  2-3-page-projet-detail: review
   2-4-page-competences-affichage-categories: ready-for-dev
   2-5-competences-cliquables-projets-lies: ready-for-dev
   2-6-page-temoignages-migrations-bdd: ready-for-dev