🎉 Init monorepo Nuxt 4 + Laravel 12 (Story 1.1)

Setup complet de l'infrastructure projet :
- Frontend Nuxt 4 (SSR, TypeScript, i18n, Pinia, TailwindCSS)
- Backend Laravel 12 API-only avec middleware X-API-Key et CORS
- Design tokens (sky-dark, sky-accent, sky-text) et polices (Merriweather, Inter)
- Documentation planning et implementation artifacts

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

api/routes/api.php

@@ -0,0 +1,7 @@
+<?php
+
+use Illuminate\Support\Facades\Route;
+
+Route::get('/health', function () {
+    return response()->json(['status' => 'ok']);
+});