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>

composer.json

@@ -12,13 +12,17 @@
     "require": {
         "php": "^8.5",
         "mintyphp/core": "*",
-        "phpmailer/phpmailer": "^7.0"
+        "phpmailer/phpmailer": "^7.0",
+        "dompdf/dompdf": "^3.1",
+        "endroid/qr-code": "^6.0",
+        "league/commonmark": "^2.8"
     },
     "require-dev": {
         "mintyphp/tools": "*",
         "mintyphp/debugger": "*",
         "phpunit/phpunit": "*",
-        "phpstan/phpstan": "^1.9"
+        "phpstan/phpstan": "^1.9",
+        "icanhazstring/composer-unused": "^0.9.6"
     },
     "autoload-dev": {
         "psr-4": {