fix(portal) : handle ticket creation error and hide new ticket button for admins

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

frontend/pages/portal/projects/[id]/index.vue

@@ -12,6 +12,7 @@
                     <h1 class="mt-1 text-xl font-bold text-primary-500 sm:text-2xl">{{ projectName }}</h1>
                 </div>
                 <NuxtLink
+                    v-if="isClient"
                     :to="`/portal/projects/${projectId}/new-ticket`"
                     class="shrink-0 rounded-md bg-primary-500 px-3 py-2 text-xs font-semibold text-white hover:bg-secondary-500 sm:px-4 sm:text-sm"
                 >
@@ -99,6 +100,7 @@ const projectName = computed(() => {
     return ''
 })
 
+const isClient = computed(() => auth.user?.roles?.includes('ROLE_CLIENT') ?? false)
 const { typeBadgeClass, statusBadgeClass, formatDate } = useClientTicketHelpers()
 
 function openDetail(ticket: ClientTicket) {

frontend/pages/portal/projects/[id]/new-ticket.vue

@@ -125,6 +125,8 @@ async function handleSubmit() {
             project: `/api/projects/${projectId.value}`,
         })
         await navigateTo(`/portal/projects/${projectId.value}`)
+    } catch {
+        // Toast already shown by useApi
     } finally {
         isSubmitting.value = false
     }