feat: registration section preferences with show_in_registration filtering and deduplication

Add show_in_registration and registration_description columns to festival_sections.
Registration form now shows deduplicated sections by name (across sub-events),
filtered by show_in_registration=true, grouped by category with card-based UI.
Section preferences use section_name instead of section_id.
Add GET/PUT registration-settings endpoints for festival-level bulk management.

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

apps/app/src/components/sections/CreateSectionDialog.vue

@@ -32,6 +32,8 @@ const form = ref({
   type: 'standard' as SectionType,
   crew_auto_accepts: false,
   responder_self_checkin: true,
+  show_in_registration: false,
+  registration_description: null as string | null,
 })
 
 const errors = ref<Record<string, string>>({})
@@ -56,6 +58,8 @@ function resetForm() {
     type: 'standard',
     crew_auto_accepts: false,
     responder_self_checkin: true,
+    show_in_registration: false,
+    registration_description: null,
   }
   errors.value = {}
   refVForm.value?.resetValidation()
@@ -76,6 +80,8 @@ function onSubmit() {
         sort_order: props.nextSortOrder,
         crew_auto_accepts: form.value.crew_auto_accepts,
         responder_self_checkin: form.value.responder_self_checkin,
+        show_in_registration: form.value.show_in_registration,
+        registration_description: form.value.registration_description || null,
       },
       {
         onSuccess: (result) => {
@@ -188,6 +194,29 @@ function onSubmit() {
                 persistent-hint
               />
             </VCol>
+            <VCol cols="12">
+              <VSwitch
+                v-model="form.show_in_registration"
+                label="Toon in vrijwilligersregistratie"
+                hint="Dit werkgebied verschijnt in het aanmeldformulier voor vrijwilligers"
+                persistent-hint
+              />
+            </VCol>
+            <VCol
+              v-if="form.show_in_registration"
+              cols="12"
+            >
+              <VTextarea
+                v-model="form.registration_description"
+                label="Beschrijving voor vrijwilligers"
+                :counter="500"
+                rows="2"
+                auto-grow
+                hint="Korte uitleg zodat vrijwilligers weten wat dit werkgebied inhoudt"
+                persistent-hint
+                :error-messages="errors.registration_description"
+              />
+            </VCol>
           </VRow>
         </VCardText>
         <VCardActions>

apps/app/src/components/sections/EditSectionDialog.vue

@@ -28,6 +28,8 @@ const form = ref({
   type: 'standard' as SectionType,
   crew_auto_accepts: false,
   responder_self_checkin: true,
+  show_in_registration: false,
+  registration_description: null as string | null,
 })
 
 const errors = ref<Record<string, string>>({})
@@ -52,6 +54,8 @@ watch(
         type: section.type,
         crew_auto_accepts: section.crew_auto_accepts,
         responder_self_checkin: section.responder_self_checkin,
+        show_in_registration: section.show_in_registration,
+        registration_description: section.registration_description,
       }
     }
   },
@@ -79,6 +83,8 @@ function onSubmit() {
         icon: form.value.icon || null,
         crew_auto_accepts: form.value.crew_auto_accepts,
         responder_self_checkin: form.value.responder_self_checkin,
+        show_in_registration: form.value.show_in_registration,
+        registration_description: form.value.registration_description || null,
       },
       {
         onSuccess: () => {
@@ -180,6 +186,29 @@ function onSubmit() {
                 persistent-hint
               />
             </VCol>
+            <VCol cols="12">
+              <VSwitch
+                v-model="form.show_in_registration"
+                label="Toon in vrijwilligersregistratie"
+                hint="Dit werkgebied verschijnt in het aanmeldformulier voor vrijwilligers"
+                persistent-hint
+              />
+            </VCol>
+            <VCol
+              v-if="form.show_in_registration"
+              cols="12"
+            >
+              <VTextarea
+                v-model="form.registration_description"
+                label="Beschrijving voor vrijwilligers"
+                :counter="500"
+                rows="2"
+                auto-grow
+                hint="Korte uitleg zodat vrijwilligers weten wat dit werkgebied inhoudt"
+                persistent-hint
+                :error-messages="errors.registration_description"
+              />
+            </VCol>
           </VRow>
         </VCardText>
         <VCardActions>

apps/app/src/types/section.ts

@@ -18,6 +18,8 @@ export interface FestivalSection {
   crew_need: number | null
   crew_auto_accepts: boolean
   responder_self_checkin: boolean
+  show_in_registration: boolean
+  registration_description: string | null
   created_at: string
 }
 
@@ -39,6 +41,8 @@ export interface Shift {
   status: ShiftStatus
   filled_slots: number
   fill_rate: number
+  is_overbooked: boolean
+  overbooking_count: number
   effective_start_time: string
   effective_end_time: string
   time_slot: TimeSlot | null
@@ -61,6 +65,8 @@ export interface CreateSectionPayload {
   sort_order?: number
   crew_auto_accepts?: boolean
   responder_self_checkin?: boolean
+  show_in_registration?: boolean
+  registration_description?: string | null
 }
 
 export interface UpdateSectionPayload extends Partial<CreateSectionPayload> {}