fix: resolve QG-001 typography token drift and QG-006 style violations

Replace raw line-height values with --leading-none/--leading-loose
design tokens in 3 CSS files. Fix 7 PHP style issues: import ordering,
unused imports, brace placement, multi-line argument formatting.

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

lib/Service/Directory/DirectorySettingsGateway.php

@@ -10,8 +10,7 @@ class DirectorySettingsGateway
     public function __construct(
         private readonly SettingsDefaultsGateway $settingsDefaultsGateway,
         private readonly SettingsAppGateway $settingsAppGateway
-    )
-    {
+    ) {
     }
 
     public function setDefaultTenantId(?int $tenantId): void