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>

lib/Repository/Support/RepoQuery.php

@@ -104,6 +104,14 @@ class RepoQuery
         }
     }
 
+    public static function uuidV4(): string
+    {
+        $data = random_bytes(16);
+        $data[6] = chr((ord($data[6]) & 0x0f) | 0x40);
+        $data[8] = chr((ord($data[8]) & 0x3f) | 0x80);
+        return vsprintf('%s%s-%s-%s-%s-%s%s%s', str_split(bin2hex($data), 4));
+    }
+
     public static function addEqualsFilter(array &$where, array &$params, $value, string $sql, bool $allowEmpty = false): void
     {
         // Use for simple "= ?" filters; skip when empty to keep WHERE clean.
@@ -117,4 +125,27 @@ class RepoQuery
         $where[] = $sql;
         $params[] = $normalized;
     }
+
+    public static function normalizeIdList($value): array
+    {
+        if (is_string($value)) {
+            $value = array_filter(array_map('trim', explode(',', $value)));
+        } elseif (!is_array($value)) {
+            return [];
+        }
+        $flat = [];
+        array_walk_recursive($value, static function ($item) use (&$flat): void {
+            $flat[] = $item;
+        });
+        $ids = [];
+        foreach ($flat as $item) {
+            $id = (int) trim((string) $item);
+            if ($id > 0) {
+                $ids[] = $id;
+            }
+        }
+        $ids = array_values(array_unique($ids));
+        sort($ids, SORT_NUMERIC);
+        return $ids;
+    }
 }