feat: registration form fields, section preferences, tag sync & schema updates

Implement EAV system for dynamic event-specific registration fields
with organisation-level templates, person section preferences with
priority ranking, and TagSyncService for deferred tag_picker sync.

New tables: registration_field_templates, registration_form_fields,
person_field_values, person_section_preferences.
New columns: persons.remarks, events.registration_show_section_preferences,
events.registration_show_availability.

58 tests, 126 assertions — all 432 tests pass (zero regressions).

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

api/app/Http/Resources/Api/V1/PersonSectionPreferenceResource.php

@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Http\Resources\Api\V1;
+
+use Illuminate\Http\Request;
+use Illuminate\Http\Resources\Json\JsonResource;
+
+final class PersonSectionPreferenceResource extends JsonResource
+{
+    public function toArray(Request $request): array
+    {
+        $section = $this->whenLoaded('festivalSection');
+
+        return [
+            'festival_section_id' => $this->festival_section_id,
+            'priority' => $this->priority,
+            'section_name' => $this->when(
+                $this->relationLoaded('festivalSection'),
+                fn () => $this->festivalSection?->name
+            ),
+            'section_icon' => $this->when(
+                $this->relationLoaded('festivalSection'),
+                fn () => $this->festivalSection?->icon
+            ),
+            'section_category' => $this->when(
+                $this->relationLoaded('festivalSection'),
+                fn () => $this->festivalSection?->category
+            ),
+        ];
+    }
+}