feat: section-based service picker + per-appointment duration override (service mode)

Service-booking mode now selects services by section like slot mode:
appointment-booking-services returns service_section per item; ServiceSlotPicker
groups by section (SearchableSelect), accumulates picks across sections into a
removable 'section -> service' chip list.

Secretaries can override a service's duration for a single appointment without
changing the service default: appointment-service-slots accepts durations[uuid]
and both create endpoints accept service_durations; the override drives total
duration and slot_end. Online (patient) booking is unaffected — it never sends
overrides. Backend + frontend tests and docs updated.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/Admin/Controller/AdminApiController.php

@@ -867,6 +867,8 @@ class AdminApiController extends BaseController
         // سرویس‌ها صرفاً پیوست می‌شوند و ساعت پایانِ دستی حفظ می‌ماند.
         $serviceUuids    = array_values(array_filter(array_map('trim', (array) ($data['service_item_uuids'] ?? []))));
         $computeDuration = (bool) ($data['duration_from_services'] ?? false);
+        // مدتِ override منشی برای همین نوبت (پیش‌فرض سرویس تغییر نمی‌کند). { uuid: minutes }
+        $durationOverrides = (array) ($data['service_durations'] ?? []);
         $serviceItems    = [];
         if (!empty($serviceUuids)) {
             $itemRepo = $this->em->getRepository(\App\ClinicService\Entity\ServiceItem::class);
@@ -880,10 +882,13 @@ class AdminApiController extends BaseController
                     if (!$item->isBookable()) {
                         return $this->error(ErrorCodes::VALIDATION, 'این سرویس برای نوبت‌دهی فعال نیست', 422, 'service_item_uuids');
                     }
-                    if (($item->getDurationMinutes() ?? 0) <= 0) {
+                    $duration = isset($durationOverrides[$u]) && (int) $durationOverrides[$u] > 0
+                        ? (int) $durationOverrides[$u]
+                        : (int) ($item->getDurationMinutes() ?? 0);
+                    if ($duration <= 0) {
                         return $this->error(ErrorCodes::VALIDATION, 'مدت سرویس تعریف نشده است', 422, 'service_item_uuids');
                     }
-                    $totalMinutes += (int) $item->getDurationMinutes();
+                    $totalMinutes += $duration;
                 }
                 $serviceItems[] = $item;
             }