diff --git a/api/app/Http/Requests/Api/V1/FormBuilder/StoreFormFieldRequest.php b/api/app/Http/Requests/Api/V1/FormBuilder/StoreFormFieldRequest.php
index 48286a84..30801bc0 100644
--- a/api/app/Http/Requests/Api/V1/FormBuilder/StoreFormFieldRequest.php
+++ b/api/app/Http/Requests/Api/V1/FormBuilder/StoreFormFieldRequest.php
@@ -7,8 +7,10 @@ namespace App\Http\Requests\Api\V1\FormBuilder;
 use App\Enums\FormBuilder\FormFieldDisplayWidth;
 use App\Enums\FormBuilder\FormFieldType;
 use App\Enums\FormBuilder\FormValueStorageHint;
+use App\Exceptions\FormBuilder\InvalidConditionalLogicSpecException;
 use App\Exceptions\FormBuilder\UnknownValidationRuleTypeException;
 use App\Models\FormBuilder\FormSchema;
+use App\Services\FormBuilder\FormFieldConditionalLogicService;
 use App\Services\FormBuilder\FormFieldValidationRuleService;
 use Illuminate\Contracts\Validation\Validator;
 use Illuminate\Foundation\Http\FormRequest;
@@ -89,6 +91,61 @@ final class StoreFormFieldRequest extends FormRequest
                     $validator->errors()->add('validation_rules', $e->getMessage());
                 }
             },
+            function (Validator $validator): void {
+                $logic = $this->input('conditional_logic');
+                if ($logic === null || $logic === [] || ! is_array($logic)) {
+                    return;
+                }
+                $root = isset($logic['show_when']) && is_array($logic['show_when'])
+                    ? $logic['show_when']
+                    : $logic;
+                $normalised = $this->normaliseLegacyGroupShape($root);
+                try {
+                    app(FormFieldConditionalLogicService::class)->assertSpecsValid($normalised);
+                } catch (InvalidConditionalLogicSpecException $e) {
+                    $validator->errors()->add('conditional_logic', $e->getMessage());
+                }
+            },
         ];
     }
+
+    /**
+     * Mirror of FormFieldService::normaliseLegacyGroupShape — translates
+     * the ARCH §8 JSON group shape (`{"all": [...]}` / `{"any": [...]}`)
+     * to the service's internal `{"operator", "children"}` form so the
+     * boundary validator can reuse the service's canonical assertion.
+     *
+     * @param  array<string, mixed>  $node
+     * @return array<string, mixed>
+     */
+    private function normaliseLegacyGroupShape(array $node): array
+    {
+        if (isset($node['field_slug'])) {
+            return $node;
+        }
+        if (isset($node['operator'], $node['children']) && is_array($node['children'])) {
+            $children = [];
+            foreach ($node['children'] as $child) {
+                if (is_array($child)) {
+                    $children[] = $this->normaliseLegacyGroupShape($child);
+                }
+            }
+
+            return ['operator' => $node['operator'], 'children' => $children];
+        }
+        foreach (['all', 'any'] as $candidate) {
+            if (isset($node[$candidate]) && is_array($node[$candidate])) {
+                $children = [];
+                foreach ($node[$candidate] as $child) {
+                    if (is_array($child)) {
+                        $children[] = $this->normaliseLegacyGroupShape($child);
+                    }
+                }
+
+                return ['operator' => $candidate, 'children' => $children];
+            }
+        }
+
+        return $node;
+    }
 }
diff --git a/api/app/Http/Requests/Api/V1/FormBuilder/UpdateFormFieldRequest.php b/api/app/Http/Requests/Api/V1/FormBuilder/UpdateFormFieldRequest.php
index dbba642b..16f92dce 100644
--- a/api/app/Http/Requests/Api/V1/FormBuilder/UpdateFormFieldRequest.php
+++ b/api/app/Http/Requests/Api/V1/FormBuilder/UpdateFormFieldRequest.php
@@ -7,8 +7,10 @@ namespace App\Http\Requests\Api\V1\FormBuilder;
 use App\Enums\FormBuilder\FormFieldDisplayWidth;
 use App\Enums\FormBuilder\FormFieldType;
 use App\Enums\FormBuilder\FormValueStorageHint;
+use App\Exceptions\FormBuilder\InvalidConditionalLogicSpecException;
 use App\Exceptions\FormBuilder\UnknownValidationRuleTypeException;
 use App\Models\FormBuilder\FormSchema;
+use App\Services\FormBuilder\FormFieldConditionalLogicService;
 use App\Services\FormBuilder\FormFieldValidationRuleService;
 use Illuminate\Contracts\Validation\Validator;
 use Illuminate\Foundation\Http\FormRequest;
@@ -89,6 +91,59 @@ final class UpdateFormFieldRequest extends FormRequest
                     $validator->errors()->add('validation_rules', $e->getMessage());
                 }
             },
+            function (Validator $validator): void {
+                if (! $this->has('conditional_logic')) {
+                    return;
+                }
+                $logic = $this->input('conditional_logic');
+                if ($logic === null || $logic === [] || ! is_array($logic)) {
+                    return;
+                }
+                $root = isset($logic['show_when']) && is_array($logic['show_when'])
+                    ? $logic['show_when']
+                    : $logic;
+                $normalised = $this->normaliseLegacyGroupShape($root);
+                try {
+                    app(FormFieldConditionalLogicService::class)->assertSpecsValid($normalised);
+                } catch (InvalidConditionalLogicSpecException $e) {
+                    $validator->errors()->add('conditional_logic', $e->getMessage());
+                }
+            },
         ];
     }
+
+    /**
+     * @param  array<string, mixed>  $node
+     * @return array<string, mixed>
+     */
+    private function normaliseLegacyGroupShape(array $node): array
+    {
+        if (isset($node['field_slug'])) {
+            return $node;
+        }
+        if (isset($node['operator'], $node['children']) && is_array($node['children'])) {
+            $children = [];
+            foreach ($node['children'] as $child) {
+                if (is_array($child)) {
+                    $children[] = $this->normaliseLegacyGroupShape($child);
+                }
+            }
+
+            return ['operator' => $node['operator'], 'children' => $children];
+        }
+        foreach (['all', 'any'] as $candidate) {
+            if (isset($node[$candidate]) && is_array($node[$candidate])) {
+                $children = [];
+                foreach ($node[$candidate] as $child) {
+                    if (is_array($child)) {
+                        $children[] = $this->normaliseLegacyGroupShape($child);
+                    }
+                }
+
+                return ['operator' => $candidate, 'children' => $children];
+            }
+        }
+
+        return $node;
+    }
 }
diff --git a/api/app/Models/FormBuilder/FormField.php b/api/app/Models/FormBuilder/FormField.php
index ee8cf880..eb2fd1c6 100644
--- a/api/app/Models/FormBuilder/FormField.php
+++ b/api/app/Models/FormBuilder/FormField.php
@@ -58,7 +58,6 @@ final class FormField extends Model
         'is_unique',
         'is_pii',
         'display_width',
-        'conditional_logic',
         'role_restrictions',
         'translations',
         'value_storage_hint',
@@ -69,7 +68,6 @@ final class FormField extends Model
     /** @var array<string, string> */
     protected $casts = [
         'options' => 'array',
-        'conditional_logic' => 'array',
         'role_restrictions' => 'array',
         'translations' => 'array',
         'is_required' => 'bool',
@@ -141,8 +139,9 @@ final class FormField extends Model
      * events are worth logging — e.g. created/deleted/restored, field_type
      * changed (value storage changes), binding changed, is_pii toggled,
      * is_filterable toggled (triggers backfill), structural options changes.
-     * NOT logged (noise): label/help_text/sort_order/conditional_logic/
-     * translations.
+     * Conditional-logic changes emit `field.conditional_logic_replaced`
+     * via FormFieldConditionalLogicService (ARCH §8; WS-5c commit 2).
+     * NOT logged (noise): label/help_text/sort_order/translations.
      *
      * Bulk-fixture suppression: the activitylog.enabled config key is the
      * kill-switch. Seeders and one-shot commands wrap themselves in
diff --git a/api/database/factories/FormBuilder/FormFieldFactory.php b/api/database/factories/FormBuilder/FormFieldFactory.php
index c2895eb4..691d3455 100644
--- a/api/database/factories/FormBuilder/FormFieldFactory.php
+++ b/api/database/factories/FormBuilder/FormFieldFactory.php
@@ -58,7 +58,6 @@ final class FormFieldFactory extends Factory
             'is_unique' => false,
             'is_pii' => false,
             'display_width' => FormFieldDisplayWidth::FULL,
-            'conditional_logic' => null,
             'role_restrictions' => null,
             'translations' => null,
             'value_storage_hint' => $fieldType->recommendedValueStorageHint(),
diff --git a/api/database/migrations/2026_04_26_100003_drop_conditional_logic_json_column.php b/api/database/migrations/2026_04_26_100003_drop_conditional_logic_json_column.php
new file mode 100644
index 00000000..42d4a9a5
--- /dev/null
+++ b/api/database/migrations/2026_04_26_100003_drop_conditional_logic_json_column.php
@@ -0,0 +1,44 @@
+<?php
+
+declare(strict_types=1);
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+/**
+ * WS-5c commit 3 — drops the `conditional_logic` JSON column on
+ * `form_fields`. By this point WS-5c commit 2's backfill has populated
+ * `form_field_conditional_logic_groups` / `form_field_conditional_logic
+ * _conditions` from the source JSON, and every reader (snapshot writer,
+ * API resources, FormFieldService cycle check) has been switched to the
+ * relational tables.
+ *
+ * Per addendum Q3, conditional_logic only applies to FormField — there is
+ * no library mirror to drop.
+ *
+ * Rollback re-adds the column as `json nullable` **without** backfilling
+ * — the rollback path is "roll back WS-5c commits 1–3 together". After
+ * this migration's `down()` the commit 2 backfill's `down()` hook
+ * reconstructs the source JSON bag.
+ */
+return new class extends Migration
+{
+    public function up(): void
+    {
+        if (Schema::hasColumn('form_fields', 'conditional_logic')) {
+            Schema::table('form_fields', function (Blueprint $table): void {
+                $table->dropColumn('conditional_logic');
+            });
+        }
+    }
+
+    public function down(): void
+    {
+        if (! Schema::hasColumn('form_fields', 'conditional_logic')) {
+            Schema::table('form_fields', function (Blueprint $table): void {
+                $table->json('conditional_logic')->nullable()->after('display_width');
+            });
+        }
+    }
+};
diff --git a/api/database/seeders/FormBuilderDevSeeder.php b/api/database/seeders/FormBuilderDevSeeder.php
index 479ee565..03669cb9 100644
--- a/api/database/seeders/FormBuilderDevSeeder.php
+++ b/api/database/seeders/FormBuilderDevSeeder.php
@@ -100,7 +100,7 @@ final class FormBuilderDevSeeder
                     'is_filterable' => $field['is_filterable'] ?? false,
                     'is_pii' => $field['is_pii'] ?? false,
                     'binding' => null, // Pattern B — snapshot embeds null for form-owned fields.
-                    'conditional_logic' => null,
+                    'conditional_logic' => null, // snapshot shape: null for fields without conditional logic
                     'translations' => null,
                     'value_storage_hint' => $field['type']->recommendedValueStorageHint()->value,
                     'sort_order' => $sortOrder + 1,
diff --git a/api/tests/Feature/FormBuilder/Bindings/FormFieldBindingMigrationTest.php b/api/tests/Feature/FormBuilder/Bindings/FormFieldBindingMigrationTest.php
index 6cb40747..9dfc41a5 100644
--- a/api/tests/Feature/FormBuilder/Bindings/FormFieldBindingMigrationTest.php
+++ b/api/tests/Feature/FormBuilder/Bindings/FormFieldBindingMigrationTest.php
@@ -39,7 +39,7 @@ final class FormFieldBindingMigrationTest extends TestCase
         // (drop-validation-cols, configs-backfill, create-configs,
         // validation-rules-backfill, create-validation-rules) +
         // 2 WS-5a migrations (drop-binding-cols, create-bindings) = 10.
-        $this->artisan('migrate:rollback', ['--step' => 10])->assertSuccessful();
+        $this->artisan('migrate:rollback', ['--step' => 11])->assertSuccessful();
         $this->assertFalse(Schema::hasTable('form_field_bindings'));
         $this->assertTrue(Schema::hasColumn('form_fields', 'binding'));
         $this->assertTrue(Schema::hasColumn('form_field_library', 'default_binding'));
@@ -101,7 +101,7 @@ final class FormFieldBindingMigrationTest extends TestCase
     public function test_rollback_reconstructs_json_and_drops_table(): void
     {
         // Walk back the full WS-5c + WS-5b + WS-5a stack (10 migrations).
-        $this->artisan('migrate:rollback', ['--step' => 10])->assertSuccessful();
+        $this->artisan('migrate:rollback', ['--step' => 11])->assertSuccessful();
         [$fieldAId, , ] = $this->seedFieldsWithBindingJson();
         [$libAId, ] = $this->seedLibraryWithBindingJson();
 
@@ -115,7 +115,7 @@ final class FormFieldBindingMigrationTest extends TestCase
         // go → restores the pre-WS-5b state (conditional-logic,
         // validation-rules and configs tables gone, validation_rules JSON
         // columns reappear on source tables; binding contract intact).
-        $this->artisan('migrate:rollback', ['--step' => 8])->assertSuccessful();
+        $this->artisan('migrate:rollback', ['--step' => 9])->assertSuccessful();
         $this->assertFalse(Schema::hasTable('form_field_conditional_logic_groups'));
         $this->assertFalse(Schema::hasTable('form_field_conditional_logic_conditions'));
         $this->assertFalse(Schema::hasTable('form_field_validation_rules'));
diff --git a/api/tests/Feature/FormBuilder/ConditionalLogic/ConditionalLogicBackfillTest.php b/api/tests/Feature/FormBuilder/ConditionalLogic/ConditionalLogicBackfillTest.php
index 5325ea46..5483fd6a 100644
--- a/api/tests/Feature/FormBuilder/ConditionalLogic/ConditionalLogicBackfillTest.php
+++ b/api/tests/Feature/FormBuilder/ConditionalLogic/ConditionalLogicBackfillTest.php
@@ -32,7 +32,7 @@ final class ConditionalLogicBackfillTest extends TestCase
     public function test_forward_backfill_builds_nested_tree_from_legacy_json(): void
     {
         // Roll back only the backfill migration (latest WS-5c step).
-        $this->artisan('migrate:rollback', ['--step' => 1])->assertSuccessful();
+        $this->artisan('migrate:rollback', ['--step' => 2])->assertSuccessful();
         $this->assertTrue(Schema::hasColumn('form_fields', 'conditional_logic'));
 
         $fieldId = $this->seedFieldWithJson([
@@ -90,9 +90,11 @@ final class ConditionalLogicBackfillTest extends TestCase
 
     public function test_rollback_reconstructs_canonical_json(): void
     {
-        // Starting state: fully migrated. Seed relational rows bypassing the
-        // service, then roll back one step (backfill) — it should repopulate
-        // the JSON column.
+        // Starting state: fully migrated. The conditional_logic column is
+        // already gone (WS-5c commit 3 drop). Seed relational rows bypassing
+        // the service, then roll back two steps — drop-column reverses first
+        // (column re-appears), then the backfill's `down()` reads relational
+        // rows and writes the JSON back.
         $org = Organisation::factory()->create();
         $schema = FormSchema::factory()->create(['organisation_id' => $org->id]);
 
@@ -105,7 +107,6 @@ final class ConditionalLogicBackfillTest extends TestCase
             'label' => 'Subject',
             'value_storage_hint' => 'json',
             'sort_order' => 0,
-            'conditional_logic' => null,
             'created_at' => now(),
             'updated_at' => now(),
         ]);
@@ -152,7 +153,7 @@ final class ConditionalLogicBackfillTest extends TestCase
         ]);
 
         // Roll back only the backfill migration — writes the JSON back.
-        $this->artisan('migrate:rollback', ['--step' => 1])->assertSuccessful();
+        $this->artisan('migrate:rollback', ['--step' => 2])->assertSuccessful();
 
         $reconstructed = DB::table('form_fields')
             ->where('id', $fieldId)
@@ -179,7 +180,7 @@ final class ConditionalLogicBackfillTest extends TestCase
 
     public function test_unknown_top_level_key_fails_migration(): void
     {
-        $this->artisan('migrate:rollback', ['--step' => 1])->assertSuccessful();
+        $this->artisan('migrate:rollback', ['--step' => 2])->assertSuccessful();
 
         $this->seedFieldWithJson([
             'hide_when' => ['all' => [['field_slug' => 'x', 'operator' => 'equals', 'value' => 1]]],
@@ -192,7 +193,7 @@ final class ConditionalLogicBackfillTest extends TestCase
 
     public function test_unknown_comparison_operator_fails_migration(): void
     {
-        $this->artisan('migrate:rollback', ['--step' => 1])->assertSuccessful();
+        $this->artisan('migrate:rollback', ['--step' => 2])->assertSuccessful();
 
         $this->seedFieldWithJson([
             'show_when' => ['all' => [['field_slug' => 'x', 'operator' => 'matches_regex', 'value' => 'y']]],
diff --git a/api/tests/Feature/FormBuilder/ConditionalLogic/ConditionalLogicJsonColumnDroppedTest.php b/api/tests/Feature/FormBuilder/ConditionalLogic/ConditionalLogicJsonColumnDroppedTest.php
new file mode 100644
index 00000000..4be33bc1
--- /dev/null
+++ b/api/tests/Feature/FormBuilder/ConditionalLogic/ConditionalLogicJsonColumnDroppedTest.php
@@ -0,0 +1,26 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Feature\FormBuilder\ConditionalLogic;
+
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Illuminate\Support\Facades\Schema;
+use Tests\TestCase;
+
+/**
+ * WS-5c commit 3 — `form_fields.conditional_logic` is gone after the full
+ * migration. Per addendum Q3, no library mirror to check.
+ */
+final class ConditionalLogicJsonColumnDroppedTest extends TestCase
+{
+    use RefreshDatabase;
+
+    public function test_form_fields_conditional_logic_column_is_dropped(): void
+    {
+        $this->assertFalse(
+            Schema::hasColumn('form_fields', 'conditional_logic'),
+            'WS-5c commit 3 must drop form_fields.conditional_logic — it now lives in the relational tree.',
+        );
+    }
+}
diff --git a/api/tests/Feature/FormBuilder/ConditionalLogic/FormFieldStrictConditionalLogicRequestTest.php b/api/tests/Feature/FormBuilder/ConditionalLogic/FormFieldStrictConditionalLogicRequestTest.php
new file mode 100644
index 00000000..c094d240
--- /dev/null
+++ b/api/tests/Feature/FormBuilder/ConditionalLogic/FormFieldStrictConditionalLogicRequestTest.php
@@ -0,0 +1,166 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Feature\FormBuilder\ConditionalLogic;
+
+use App\Enums\FormBuilder\FormFieldType;
+use App\Models\FormBuilder\FormField;
+use App\Models\FormBuilder\FormSchema;
+use App\Models\Organisation;
+use App\Models\User;
+use Database\Seeders\RoleSeeder;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Laravel\Sanctum\Sanctum;
+use Tests\TestCase;
+
+/**
+ * WS-5c commit 3 — strict validator on save. The Store/Update
+ * FormRequests' `after()` hook delegates to
+ * `FormFieldConditionalLogicService::assertSpecsValid`, so bad specs
+ * fail at the HTTP boundary before any write lands.
+ */
+final class FormFieldStrictConditionalLogicRequestTest extends TestCase
+{
+    use RefreshDatabase;
+
+    private Organisation $org;
+
+    private User $admin;
+
+    private FormSchema $schema;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+        $this->seed(RoleSeeder::class);
+        $this->org = Organisation::factory()->create();
+        $this->admin = User::factory()->create();
+        $this->org->users()->attach($this->admin, ['role' => 'org_admin']);
+        $this->schema = FormSchema::factory()->create(['organisation_id' => $this->org->id]);
+    }
+
+    public function test_store_rejects_unknown_comparison_operator(): void
+    {
+        Sanctum::actingAs($this->admin);
+
+        FormField::factory()->create(['form_schema_id' => $this->schema->id, 'slug' => 'gate']);
+
+        $response = $this->postJson(
+            "/api/v1/organisations/{$this->org->id}/forms/schemas/{$this->schema->id}/fields",
+            [
+                'field_type' => FormFieldType::TEXT->value,
+                'slug' => 'target',
+                'label' => 'Target',
+                'conditional_logic' => [
+                    'show_when' => [
+                        'all' => [
+                            ['field_slug' => 'gate', 'operator' => 'matches_regex', 'value' => 'y'],
+                        ],
+                    ],
+                ],
+            ],
+        );
+
+        $response->assertStatus(422);
+        $response->assertJsonValidationErrors(['conditional_logic']);
+    }
+
+    public function test_store_rejects_root_condition_without_group(): void
+    {
+        Sanctum::actingAs($this->admin);
+
+        $response = $this->postJson(
+            "/api/v1/organisations/{$this->org->id}/forms/schemas/{$this->schema->id}/fields",
+            [
+                'field_type' => FormFieldType::TEXT->value,
+                'slug' => 'target',
+                'label' => 'Target',
+                // Condition at root — invalid; ARCH §8 requires a group wrapper.
+                'conditional_logic' => [
+                    'show_when' => [
+                        'field_slug' => 'gate',
+                        'operator' => 'equals',
+                        'value' => 'y',
+                    ],
+                ],
+            ],
+        );
+
+        $response->assertStatus(422);
+        $response->assertJsonValidationErrors(['conditional_logic']);
+    }
+
+    public function test_store_rejects_empty_group(): void
+    {
+        Sanctum::actingAs($this->admin);
+
+        $response = $this->postJson(
+            "/api/v1/organisations/{$this->org->id}/forms/schemas/{$this->schema->id}/fields",
+            [
+                'field_type' => FormFieldType::TEXT->value,
+                'slug' => 'target',
+                'label' => 'Target',
+                'conditional_logic' => ['show_when' => ['all' => []]],
+            ],
+        );
+
+        $response->assertStatus(422);
+        $response->assertJsonValidationErrors(['conditional_logic']);
+    }
+
+    public function test_store_rejects_unknown_field_slug(): void
+    {
+        Sanctum::actingAs($this->admin);
+
+        $response = $this->postJson(
+            "/api/v1/organisations/{$this->org->id}/forms/schemas/{$this->schema->id}/fields",
+            [
+                'field_type' => FormFieldType::TEXT->value,
+                'slug' => 'target',
+                'label' => 'Target',
+                'conditional_logic' => [
+                    'show_when' => [
+                        'all' => [
+                            ['field_slug' => 'nonexistent', 'operator' => 'equals', 'value' => 'y'],
+                        ],
+                    ],
+                ],
+            ],
+        );
+
+        $response->assertStatus(422);
+        $this->assertStringContainsString('nonexistent', (string) $response->json('message'));
+    }
+
+    public function test_store_accepts_valid_tree_and_persists_relational_rows(): void
+    {
+        Sanctum::actingAs($this->admin);
+        FormField::factory()->create(['form_schema_id' => $this->schema->id, 'slug' => 'gate']);
+
+        $response = $this->postJson(
+            "/api/v1/organisations/{$this->org->id}/forms/schemas/{$this->schema->id}/fields",
+            [
+                'field_type' => FormFieldType::TEXT->value,
+                'slug' => 'target',
+                'label' => 'Target',
+                'conditional_logic' => [
+                    'show_when' => [
+                        'all' => [
+                            ['field_slug' => 'gate', 'operator' => 'equals', 'value' => 'yes'],
+                        ],
+                    ],
+                ],
+            ],
+        );
+
+        $response->assertStatus(201);
+        $this->assertSame([
+            'show_when' => [
+                'all' => [
+                    ['field_slug' => 'gate', 'operator' => 'equals', 'value' => 'yes'],
+                ],
+            ],
+        ], $response->json('data.conditional_logic'));
+    }
+}
diff --git a/api/tests/Feature/FormBuilder/Configs/FormFieldConfigBackfillAndDropTest.php b/api/tests/Feature/FormBuilder/Configs/FormFieldConfigBackfillAndDropTest.php
index cd210440..0543e1ee 100644
--- a/api/tests/Feature/FormBuilder/Configs/FormFieldConfigBackfillAndDropTest.php
+++ b/api/tests/Feature/FormBuilder/Configs/FormFieldConfigBackfillAndDropTest.php
@@ -30,7 +30,7 @@ final class FormFieldConfigBackfillAndDropTest extends TestCase
         // Roll back 2 WS-5c migrations + 5 WS-5b migrations = 7, to get the
         // pre-WS-5b state where the JSON column still exists on form_fields
         // / form_field_library.
-        $this->artisan('migrate:rollback', ['--step' => 8])->assertSuccessful();
+        $this->artisan('migrate:rollback', ['--step' => 9])->assertSuccessful();
         $this->assertTrue(Schema::hasColumn('form_fields', 'validation_rules'));
 
         $fieldId = $this->seedField([
diff --git a/api/tests/Feature/FormBuilder/ValidationRules/FormFieldValidationRuleBackfillTest.php b/api/tests/Feature/FormBuilder/ValidationRules/FormFieldValidationRuleBackfillTest.php
index 6274ac7c..750a5c4b 100644
--- a/api/tests/Feature/FormBuilder/ValidationRules/FormFieldValidationRuleBackfillTest.php
+++ b/api/tests/Feature/FormBuilder/ValidationRules/FormFieldValidationRuleBackfillTest.php
@@ -37,7 +37,7 @@ final class FormFieldValidationRuleBackfillTest extends TestCase
         // validation-rules-backfill + create-validation-rules) = 7.
         // Brings us to the pre-WS-5b state: validation_rules JSON column
         // present, no relational tables for WS-5b.
-        $this->artisan('migrate:rollback', ['--step' => 8])->assertSuccessful();
+        $this->artisan('migrate:rollback', ['--step' => 9])->assertSuccessful();
         $this->assertFalse(Schema::hasTable('form_field_validation_rules'));
         $this->assertTrue(Schema::hasColumn('form_fields', 'validation_rules'));
 
@@ -98,7 +98,7 @@ final class FormFieldValidationRuleBackfillTest extends TestCase
         // (validation_rules JSON column present; no relational tables for
         // WS-5b). Step count: drop-cols + configs-backfill + create-configs
         // + validation-rules-backfill + create-validation-rules = 5.
-        $this->artisan('migrate:rollback', ['--step' => 8])->assertSuccessful();
+        $this->artisan('migrate:rollback', ['--step' => 9])->assertSuccessful();
 
         $fieldId = $this->seedFieldWithJson([
             'field_type' => 'TAG_PICKER',
@@ -122,7 +122,7 @@ final class FormFieldValidationRuleBackfillTest extends TestCase
         // (validation_rules JSON column present; no relational tables for
         // WS-5b). Step count: drop-cols + configs-backfill + create-configs
         // + validation-rules-backfill + create-validation-rules = 5.
-        $this->artisan('migrate:rollback', ['--step' => 8])->assertSuccessful();
+        $this->artisan('migrate:rollback', ['--step' => 9])->assertSuccessful();
 
         $fieldId = $this->seedFieldWithJson([
             'field_type' => 'TEXT',
@@ -149,7 +149,7 @@ final class FormFieldValidationRuleBackfillTest extends TestCase
         // (validation_rules JSON column present; no relational tables for
         // WS-5b). Step count: drop-cols + configs-backfill + create-configs
         // + validation-rules-backfill + create-validation-rules = 5.
-        $this->artisan('migrate:rollback', ['--step' => 8])->assertSuccessful();
+        $this->artisan('migrate:rollback', ['--step' => 9])->assertSuccessful();
 
         $this->seedFieldWithJson([
             'field_type' => 'TEXT',
@@ -166,7 +166,7 @@ final class FormFieldValidationRuleBackfillTest extends TestCase
         // (validation_rules JSON column present; no relational tables for
         // WS-5b). Step count: drop-cols + configs-backfill + create-configs
         // + validation-rules-backfill + create-validation-rules = 5.
-        $this->artisan('migrate:rollback', ['--step' => 8])->assertSuccessful();
+        $this->artisan('migrate:rollback', ['--step' => 9])->assertSuccessful();
 
         $this->seedFieldWithJson([
             'field_type' => 'BOOLEAN',
@@ -185,7 +185,7 @@ final class FormFieldValidationRuleBackfillTest extends TestCase
         // full-back-then-full-forward cycle — rolling back all WS-5b
         // migrations restores the pre-WS-5b state (columns present on
         // source tables; validation rules relational table gone).
-        $this->artisan('migrate:rollback', ['--step' => 8])->assertSuccessful();
+        $this->artisan('migrate:rollback', ['--step' => 9])->assertSuccessful();
         [$numberId] = $this->seedFields();
 
         $this->artisan('migrate')->assertSuccessful();
@@ -200,7 +200,7 @@ final class FormFieldValidationRuleBackfillTest extends TestCase
 
         // Roll back WS-5b fully → column reappears and carries canonical JSON
         // reconstructed from the relational rows.
-        $this->artisan('migrate:rollback', ['--step' => 8])->assertSuccessful();
+        $this->artisan('migrate:rollback', ['--step' => 9])->assertSuccessful();
         $this->assertTrue(Schema::hasColumn('form_fields', 'validation_rules'));
 
         $field = DB::table('form_fields')->where('id', $numberId)->first();