feat: split name into first_name + last_name across users, persons, and companies

Cross-cutting migration affecting the entire stack:
- Database: 3 migrations splitting name columns with data migration
- Models: first_name/last_name on User, Person; contact_first_name/contact_last_name on Company; backward-compatible name accessors
- API: all resources return first_name, last_name, full_name; assignablePersons endpoint updated
- Requests: validation rules updated for all person/user/company forms
- Services: VolunteerRegistrationService, ShiftAssignmentService, InvitationService updated
- Frontend: TypeScript types, Zod schemas, all forms split into Voornaam/Achternaam fields
- Display: all person/user name references use full_name; initials use first_name[0]+last_name[0]
- Tests: all 371 tests passing
- Docs: SCHEMA.md and API.md updated

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

apps/app/src/components/events/EventTabsNav.vue

@@ -4,6 +4,7 @@ import { dutchPlural } from '@/lib/dutch-plural'
 import { useAuthStore } from '@/stores/useAuthStore'
 import { useOrganisationStore } from '@/stores/useOrganisationStore'
 import EditEventDialog from '@/components/events/EditEventDialog.vue'
+import RegistrationLinkCard from '@/components/events/RegistrationLinkCard.vue'
 import type { EventStatus } from '@/types/event'
 
 const route = useRoute()
@@ -177,6 +178,12 @@ const backRoute = computed(() => {
         </VBtn>
       </div>
 
+      <!-- Registration link (top-level events only) -->
+      <RegistrationLinkCard
+        v-if="!event.parent_event_id"
+        :event="event"
+      />
+
       <!-- Horizontal tabs -->
       <VTabs
         :model-value="activeTab"

apps/app/src/components/events/RegistrationLinkCard.vue

@@ -0,0 +1,73 @@
+<script setup lang="ts">
+import type { EventItem } from '@/types/event'
+
+const props = defineProps<{
+  event: EventItem
+}>()
+
+const portalBaseUrl = import.meta.env.VITE_PORTAL_URL || 'https://portal.crewli.app'
+
+const registrationUrl = computed(() =>
+  `${portalBaseUrl}/register/${props.event.slug}`,
+)
+
+const isRegistrationOpen = computed(() =>
+  props.event.status === 'registration_open',
+)
+
+const copied = ref(false)
+
+async function copyLink() {
+  await navigator.clipboard.writeText(registrationUrl.value)
+  copied.value = true
+  setTimeout(() => { copied.value = false }, 2000)
+}
+</script>
+
+<template>
+  <VCard
+    v-if="event"
+    variant="outlined"
+    class="mb-4"
+  >
+    <VCardText>
+      <div class="d-flex align-center justify-space-between flex-wrap ga-2">
+        <div>
+          <div class="text-subtitle-2 text-medium-emphasis mb-1">
+            Vrijwilligersregistratie
+          </div>
+          <template v-if="isRegistrationOpen">
+            <code class="text-body-2">{{ registrationUrl }}</code>
+          </template>
+          <template v-else>
+            <span class="text-body-2 text-medium-emphasis">
+              Zet de status op 'Registratie open' om het formulier te activeren.
+            </span>
+          </template>
+        </div>
+        <div
+          v-if="isRegistrationOpen"
+          class="d-flex ga-2"
+        >
+          <VBtn
+            size="small"
+            variant="outlined"
+            prepend-icon="tabler-copy"
+            @click="copyLink"
+          >
+            {{ copied ? 'Gekopieerd!' : 'Kopieer link' }}
+          </VBtn>
+          <VBtn
+            size="small"
+            variant="outlined"
+            prepend-icon="tabler-external-link"
+            :href="registrationUrl"
+            target="_blank"
+          >
+            Open formulier
+          </VBtn>
+        </div>
+      </div>
+    </VCardText>
+  </VCard>
+</template>