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>

pages/auth/login().php

@@ -88,14 +88,14 @@ $resolveLoginCandidates = static function (string $inputEmail) use ($userReadRep
     $isKnownActiveUser = $user && (int) ($user['active'] ?? 0) === 1 && (int) ($user['id'] ?? 0) > 0;
 
     $tenants = [];
-    $discovery = false;
-
     if ($isKnownActiveUser) {
         $userId = (int) $user['id'];
         $tenants = $userTenantContextService->getAssignedActiveTenants($userId);
     }
 
     // Fallback: domain-based SSO discovery for users not yet provisioned locally
+    $discovery = false;
+    $discoveryMethodsByTenantId = [];
     if (!$tenants) {
         $discoveryResults = $tenantSsoService->discoverTenantsByEmailDomain($emailValue);
         if (!$discoveryResults) {
@@ -103,7 +103,6 @@ $resolveLoginCandidates = static function (string $inputEmail) use ($userReadRep
         }
         $discovery = true;
         $tenants = array_map(static fn (array $r): array => $r['tenant'], $discoveryResults);
-        $discoveryMethodsByTenantId = [];
         foreach ($discoveryResults as $r) {
             $discoveryMethodsByTenantId[(int) $r['id']] = $r['methods'];
         }
@@ -120,6 +119,7 @@ $resolveLoginCandidates = static function (string $inputEmail) use ($userReadRep
         if ($tenantSlug === '') {
             continue;
         }
+        /** @phpstan-ignore ternary.alwaysFalse ($discovery is set to true inside the !$tenants branch that also reassigns $tenants) */
         $methods = $discovery
             ? ($discoveryMethodsByTenantId[$tenantId] ?? ['local' => false, 'microsoft' => false, 'microsoft_reason' => '', 'ldap' => false, 'ldap_reason' => ''])
             : $tenantSsoService->resolveTenantLoginMethods($tenantId);