feat: demotion of user accounts via crm

tests/Entity/UserTest.php

@@ -77,6 +77,47 @@ class UserTest extends TestCase
         $this->assertCount(0, $this->validate($user));
     }
 
+    public function testSetDisabledBlocksAndUnblocksTheAccount(): void
+    {
+        $user = new User();
+
+        $user->setDisabled(true);
+
+        $this->assertTrue($user->isDisabled());
+        $this->assertNotNull($user->getDisabledAt());
+
+        $user
+            ->setDisabledReason('Gesperrt.')
+            ->setDisabledReasonInternal('Siehe Vorgang 4711.')
+            ->setDisabled(false)
+        ;
+
+        $this->assertFalse($user->isDisabled());
+        $this->assertNull($user->getDisabledAt());
+        $this->assertNull($user->getDisabledReason());
+        $this->assertNull($user->getDisabledReasonInternal());
+    }
+
+    public function testSetDisabledKeepsTheOriginalTimestampWhenTheStateIsUnchanged(): void
+    {
+        $disabledAt = new \DateTimeImmutable('2026-01-01 08:00:00');
+
+        $user = (new User())
+            ->setDisabledAt($disabledAt)
+            ->setDisabledReason('Gesperrt.')
+        ;
+
+        $user->setDisabled(true);
+
+        $this->assertSame($disabledAt, $user->getDisabledAt());
+        $this->assertSame('Gesperrt.', $user->getDisabledReason());
+
+        $enabled = new User();
+        $enabled->setDisabled(false);
+
+        $this->assertNull($enabled->getDisabledAt());
+    }
+
     private function validate(User $user): ConstraintViolationListInterface
     {
         return Validation::createValidatorBuilder()