fix(model-types) : extract error field from 409 response for user-friendly messages

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/composables/useEntityTypes.ts

@@ -127,8 +127,8 @@ export function useEntityTypes(config: EntityTypeConfig) {
       showSuccess(`Type de ${label} "${data.name}" créé`)
       return { success: true, data: normalized }
     } catch (error) {
-      const err = error as Error & { data?: { message?: string }; message?: string }
-      const raw = err?.data?.message || err?.message
+      const err = error as Error & { data?: { error?: string; message?: string }; message?: string }
+      const raw = err?.data?.error || err?.data?.message || err?.message
       const message = humanizeError(raw)
       showError(`Impossible de créer le type de ${label} : ${message}`)
       return { success: false, error: message }
@@ -153,8 +153,8 @@ export function useEntityTypes(config: EntityTypeConfig) {
       showSuccess(`Type de ${label} "${data.name}" mis à jour`)
       return { success: true, data: normalized }
     } catch (error) {
-      const err = error as Error & { data?: { message?: string }; message?: string }
-      const raw = err?.data?.message || err?.message
+      const err = error as Error & { data?: { error?: string; message?: string }; message?: string }
+      const raw = err?.data?.error || err?.data?.message || err?.message
       const message = humanizeError(raw)
       showError(`Impossible de mettre à jour le type de ${label} : ${message}`)
       return { success: false, error: message }
@@ -171,8 +171,8 @@ export function useEntityTypes(config: EntityTypeConfig) {
       showSuccess(`Type de ${label} supprimé`)
       return { success: true }
     } catch (error) {
-      const err = error as Error & { data?: { message?: string }; message?: string }
-      const raw = err?.data?.message || err?.message
+      const err = error as Error & { data?: { error?: string; message?: string }; message?: string }
+      const raw = err?.data?.error || err?.data?.message || err?.message
       const message = humanizeError(raw)
       showError(`Impossible de supprimer le type de ${label} : ${message}`)
       return { success: false, error: message }