refactor(form-builder): strict validator on save; strip rules.unique fallback

api/tests/Feature/FormBuilder/ValidationRules/UniqueJsonFallbackRemovedTest.php

@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Feature\FormBuilder\ValidationRules;
+
+use PHPUnit\Framework\TestCase;
+
+/**
+ * WS-5b consolidation — static guard that the legacy
+ * `validation_rules.unique` JSON fallback has been stripped from
+ * `FormValueService`. The is_unique column is the single source of truth.
+ *
+ * We assert the textual absence rather than a behavioural test: uniqueness
+ * enforcement is heavily coupled to the FormValueObserver typed-column
+ * write path, submission status, etc. The cheap + high-signal check is
+ * "the code no longer references `$rules['unique']`".
+ */
+final class UniqueJsonFallbackRemovedTest extends TestCase
+{
+    public function test_form_value_service_no_longer_reads_rules_unique_key(): void
+    {
+        $source = (string) file_get_contents(
+            __DIR__.'/../../../../app/Services/FormBuilder/FormValueService.php',
+        );
+
+        $this->assertStringNotContainsString("\$rules['unique']", $source);
+        $this->assertStringNotContainsString('$rules["unique"]', $source);
+    }
+}