✨ Add skills page with category grouping (Story 2.4)

- Enhance Skill model with getCurrentLevel() and ordered scope
- Update SkillController to group by category with translated labels
- Add level and project_count to SkillResource
- Create skill.ts types (Skill, SkillCategory, SkillsResponse)
- Create useFetchSkills composable
- Create SkillCard component with animated progress bar
- Implement competences.vue with:
  - Responsive grid (2/3/4 columns)
  - Category sections with icons
  - Stagger animations (respects prefers-reduced-motion)
  - Loading/error/empty states
  - Placeholder for vis.js skill tree (Epic 3)

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

api/app/Http/Resources/SkillResource.php

@@ -16,7 +16,10 @@ class SkillResource extends JsonResource
             'description' => $this->getTranslated('description_key'),
             'icon' => $this->icon,
             'category' => $this->category,
+            'level' => $this->getCurrentLevel(),
             'max_level' => $this->max_level,
+            'display_order' => $this->display_order,
+            'project_count' => $this->whenLoaded('projects', fn () => $this->projects->count()),
             'pivot' => $this->when($this->pivot, fn () => [
                 'level_before' => $this->pivot->level_before,
                 'level_after' => $this->pivot->level_after,