Add organizer registration test, User entity tests, and testing rules to CLAUDE.md

- Add testRegistrationAsOrganizer to RegistrationControllerTest
- Add testOrganizerFields and testOrganizerFieldsDefaultToNull to UserTest
- Add testing rules to CLAUDE.md: always create tests, run after changes, 100% coverage

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/Entity/UserTest.php

@@ -56,6 +56,38 @@ class UserTest extends TestCase
         self::assertSame('hashed', $user->getPassword());
     }
 
+    public function testOrganizerFields(): void
+    {
+        $user = new User();
+
+        $result = $user->setCompanyName('Mon Asso')
+            ->setSiret('12345678901234')
+            ->setAddress('12 rue de la Paix')
+            ->setPostalCode('75001')
+            ->setCity('Paris')
+            ->setPhone('0612345678');
+
+        self::assertSame($user, $result);
+        self::assertSame('Mon Asso', $user->getCompanyName());
+        self::assertSame('12345678901234', $user->getSiret());
+        self::assertSame('12 rue de la Paix', $user->getAddress());
+        self::assertSame('75001', $user->getPostalCode());
+        self::assertSame('Paris', $user->getCity());
+        self::assertSame('0612345678', $user->getPhone());
+    }
+
+    public function testOrganizerFieldsDefaultToNull(): void
+    {
+        $user = new User();
+
+        self::assertNull($user->getCompanyName());
+        self::assertNull($user->getSiret());
+        self::assertNull($user->getAddress());
+        self::assertNull($user->getPostalCode());
+        self::assertNull($user->getCity());
+        self::assertNull($user->getPhone());
+    }
+
     public function testEraseCredentialsDoesNotThrow(): void
     {
         $user = new User();