feat(01-02): create useProjects() composable with i18n support

- useProjects() returns projects, featuredProjects, filterByCategory, search, findById
- Added title/description/longDescription fields to Project interface
- Uses Nuxt auto-imports (computed, useI18n, Ref)
- i18n keys follow projects.${id}.title pattern

shared/types/index.ts

@@ -5,6 +5,9 @@ export interface ProjectButton {
 
 export interface Project {
   id: string
+  title: string
+  description: string
+  longDescription?: string
   image: string
   technologies: string[]
   category: string