refactor(api): extract shared extractCollection helper (F2.1)

Create shared/utils/apiHelpers.ts with generic extractCollection<T>()
that handles hydra:member, member, items, data, and array formats.
Replace 7 local implementations in CRUD composables.

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

app/composables/useSites.ts

@@ -1,6 +1,7 @@
 import { ref } from 'vue'
 import { useToast } from './useToast'
 import { useApi } from './useApi'
+import { extractCollection } from '~/shared/utils/apiHelpers'
 
 export interface Site {
   id: string
@@ -24,23 +25,6 @@ interface SiteResult {
 const sites = ref<Site[]>([])
 const loading = ref(false)
 
-const extractCollection = (payload: unknown): Site[] => {
-  if (Array.isArray(payload)) {
-    return payload as Site[]
-  }
-  const p = payload as Record<string, unknown> | null
-  if (Array.isArray(p?.member)) {
-    return p.member as Site[]
-  }
-  if (Array.isArray(p?.['hydra:member'])) {
-    return p['hydra:member'] as Site[]
-  }
-  if (Array.isArray(p?.data)) {
-    return p.data as Site[]
-  }
-  return []
-}
-
 export function useSites() {
   const { showSuccess, showInfo } = useToast()
   const { get, post, patch, delete: del } = useApi()
@@ -49,8 +33,6 @@ export function useSites() {
     loading.value = true
     try {
       const result = await get('/sites')
-      console.log('sites api result', result)
-
       if (result.success) {
         const collection = extractCollection(result.data)
         sites.value = collection