feat(form-builder): FormFieldValidationRuleService + legacy backfill + snapshot + library row-copy

api/database/seeders/FormBuilderDevSeeder.php

@@ -308,9 +308,12 @@ final class FormBuilderDevSeeder
                 'slug' => 'sectie_voorkeur',
                 'label' => 'Bij welke sectie wil je het liefst werken?',
                 'help_text' => 'Sleep je voorkeuren in volgorde. Nummer 1 is je eerste keuze.',
-                // UI soft cap; the hard cap of 5 lives in
-                // FormValueService shape validation.
-                'validation_rules' => ['max_priorities' => 3],
+                // UI soft cap (hard cap of 5 is in FormValueService shape
+                // validation). Post-WS-5b the UI cap lives as a relational
+                // row with rule_type `max_selected` — see
+                // seedEventRegistrationShowcaseSchema() which populates it
+                // via FormFieldValidationRuleService.
+                'max_selected_ui_cap' => 3,
                 'is_required' => false,
                 'is_filterable' => false,
                 'display_width' => 'full',
@@ -357,8 +360,10 @@ final class FormBuilderDevSeeder
             'version' => 1,
         ]);
 
+        $ruleService = app(\App\Services\FormBuilder\FormFieldValidationRuleService::class);
+
         foreach (self::showcaseFieldDefinitions() as $sortOrder => $def) {
-            FormField::create([
+            $field = FormField::create([
                 'form_schema_id' => $schema->id,
                 'field_type' => $def['type']->value,
                 'slug' => $def['slug'],
@@ -376,6 +381,16 @@ final class FormBuilderDevSeeder
                 'value_storage_hint' => $def['value_storage_hint'] ?? FormValueStorageHint::JSON,
                 'sort_order' => $sortOrder + 1,
             ]);
+
+            // Relational validation rules (WS-5b). The SECTION_PRIORITY
+            // field carries the UI soft cap as a `max_selected` row; other
+            // fields in the showcase have no rules yet.
+            if (isset($def['max_selected_ui_cap'])) {
+                $ruleService->replaceRules($field, [[
+                    'rule_type' => \App\Enums\FormBuilder\FormFieldValidationRuleType::MaxSelected->value,
+                    'parameters' => ['value' => (int) $def['max_selected_ui_cap']],
+                ]]);
+            }
         }
 
         return $schema->refresh();