fix: resolve all quality gate failures — i18n key, typography tokens, PHPStan errors, style

- Add missing i18n key "LDAP attribute map could not be encoded" (de+en)
- Replace raw font-weight/line-height with design tokens in app-topbar.css
- Fix import ordering in SchedulerRunService.php (php-cs-fixer)
- Fix PHPStan mock chain errors in DebitorDetailServiceTest and TenantSsoServiceTest (PHPUnit 12 API)
- Simplify redundant comparison in NotificationService dedupe window
- Add PHPStan type hint for mock callback array in SchedulerJobFailedNotificationListenerTest
- Fix undefined variable and add flow-analysis suppression in login().php
- Increase dev PHP memory_limit to 1G for PHPStan (prod stays 256M)

All 6 quality gates now pass: QG-001 (1618 tests), QG-002 (0 errors),
QG-003 (6630 assertions), QG-006 (0 fixable), QG-008, QG-009.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/Service/Auth/TenantSsoServiceTest.php

@@ -467,7 +467,7 @@ class TenantSsoServiceTest extends TestCase
         $tenantGateway->method('findById')->willReturn(['id' => 5, 'status' => 'active', 'uuid' => 'abc', 'description' => 'Acme']);
 
         $microsoftRepo = $this->createMock(TenantMicrosoftAuthRepositoryInterface::class);
-        $microsoftRepo->method('findEnabledWithExplicitDomain')->with('acme.com')->willReturn([
+        $microsoftRepo->expects($this->any())->method('findEnabledWithExplicitDomain')->with('acme.com')->willReturn([
             ['tenant_id' => 5, 'allowed_domains' => 'acme.com'],
         ]);
         $microsoftRepo->method('findByTenantId')->willReturn([