feat: add API optimizations, cache invalidation and comprehensive test suite

- Add abort controllers and request deduplication to composables
- Add entity type cache invalidation on create/update/delete flows
- Add 179 new tests (utilities, services, composables, components)
- Fix Vue runtime warnings in structure editors

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/composables/useSites.ts

@@ -24,19 +24,21 @@ interface SiteResult {
 
 const sites = ref<Site[]>([])
 const loading = ref(false)
+const loaded = ref(false)
 
 export function useSites() {
-  const { showSuccess, showInfo } = useToast()
+  const { showSuccess } = useToast()
   const { get, post, patch, delete: del } = useApi()
 
-  const loadSites = async (): Promise<void> => {
+  const loadSites = async (options: { force?: boolean } = {}): Promise<void> => {
+    if (!options.force && loaded.value) return
     loading.value = true
     try {
       const result = await get('/sites')
       if (result.success) {
         const collection = extractCollection(result.data)
         sites.value = collection
-        showInfo(`Chargement de ${collection.length} site(s) réussi`)
+        loaded.value = true
       }
     } catch (error) {
       console.error('Erreur lors du chargement des sites:', error)