feat(form-builder): form_field_configs relational table + non-validation key split + drop validation_rules JSON columns

api/app/Enums/FormBuilder/FormFieldConfigType.php

@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Enums\FormBuilder;
+
+/**
+ * Non-validation field configuration (ARCH-FORM-BUILDER §17.5). Tag
+ * picker option filtering + upload disk selection live here because
+ * they are per-field rendering / storage configuration, not validation
+ * rules — splitting them out of `form_field_validation_rules` preserves
+ * the semantic integrity of that table's name (strict-enterprise
+ * decision on WS-5b, addendum Q3 Uitvoering).
+ *
+ * Per-case parameter shape is enforced at the service layer
+ * (`FormFieldConfigService::assertSpecValid`), not in the enum or DB.
+ */
+enum FormFieldConfigType: string
+{
+    case TagCategories = 'tag_categories';
+    case StorageDisk = 'storage_disk';
+}