🌐 Add full i18n system frontend + API (Story 1.3)

Nuxt i18n with lazy-loaded JSON files, localized routes, hreflang SEO tags,
LanguageSwitcher component. Laravel SetLocale middleware, HasTranslations trait,
API Resources and Controllers for projects/skills with Accept-Language support.

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

api/bootstrap/app.php

@@ -12,6 +12,7 @@ return Application::configure(basePath: dirname(__DIR__))
     )
     ->withMiddleware(function (Middleware $middleware): void {
         $middleware->api(append: [
+            \App\Http\Middleware\SetLocale::class,
             \App\Http\Middleware\VerifyApiKey::class,
         ]);
     })