add composer-unused, comprehensive docs, and project restructure

- Add icanhazstring/composer-unused as dev dependency for dependency hygiene checks
- Add German documentation (docs/) covering architecture, conventions, workflows, and developer checklists
- Add API layer (ApiAuth, ApiBootstrap, ApiResponse), audit, scheduler, custom fields, and SSO services
- Add Microsoft OIDC SSO, API token management, and user lifecycle features
- Add swagger-ui vendor integration and OpenAPI spec
- Add production Docker setup and bin/ scripts
- Update composer dependencies, config, templates, and frontend assets throughout

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

pages/admin/roles/create(default).phtml

@@ -15,21 +15,29 @@
       ['label' => t('Create role')],
     ];
     require templatePath('partials/app-breadcrumb.phtml');
+    $titlebar = [
+      'title' => t('Create role'),
+      'backHref' => 'admin/roles',
+      'backTitle' => t('Cancel'),
+      'actions' => [
+        [
+          'form' => 'role-form',
+          'name' => 'action',
+          'value' => 'create',
+          'class' => 'secondary outline',
+          'label' => t('Create'),
+        ],
+        [
+          'form' => 'role-form',
+          'name' => 'action',
+          'value' => 'create_close',
+          'class' => 'primary',
+          'label' => t('Create & close'),
+        ],
+      ],
+    ];
+    require templatePath('partials/app-details-titlebar.phtml');
     ?>
-    <div class="app-details-titlebar">
-      <h1>
-        <a href="admin/roles" title="<?php e(t('Cancel')); ?>"><i class="bi bi-arrow-left"></i></a>
-        <?php e(t('Create role')); ?>
-      </h1>
-      <div class="app-details-titlebar-actions">
-        <button type="submit" form="role-form" name="action" value="create" class="secondary outline">
-          <?php e(t('Create')); ?>
-        </button>
-        <button type="submit" form="role-form" name="action" value="create_close" class="primary">
-          <?php e(t('Create & close')); ?>
-        </button>
-      </div>
-    </div>
     <?php if (!empty($errors)): ?>
       <div class="notice" data-variant="error">
         <ul>