🌐 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/app/Http/Resources/SkillResource.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace App\Http\Resources;
+
+use Illuminate\Http\Request;
+use Illuminate\Http\Resources\Json\JsonResource;
+
+class SkillResource extends JsonResource
+{
+    public function toArray(Request $request): array
+    {
+        return [
+            'id' => $this->id,
+            'slug' => $this->slug,
+            'name' => $this->getTranslated('name_key'),
+            'description' => $this->getTranslated('description_key'),
+            'icon' => $this->icon,
+            'category' => $this->category,
+            'max_level' => $this->max_level,
+            'pivot' => $this->when($this->pivot, fn () => [
+                'level_before' => $this->pivot->level_before,
+                'level_after' => $this->pivot->level_after,
+            ]),
+        ];
+    }
+}