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>

docker-compose.prod.yml

@@ -0,0 +1,69 @@
+services:
+  nginx:
+    image: nginx:1.25-alpine
+    ports:
+      - "80:80"
+      - "443:443"
+    volumes:
+      - ./:/var/www
+      - ./docker/nginx/prod.conf:/etc/nginx/conf.d/default.conf:ro
+      - ./docker/nginx/certs:/etc/nginx/certs:ro
+    depends_on:
+      - php
+    restart: unless-stopped
+
+  php:
+    build:
+      context: .
+      dockerfile: docker/php/Dockerfile
+    env_file:
+      - .env
+    environment:
+      APP_ENV: prod
+      APP_DEBUG: "0"
+    volumes:
+      - ./:/var/www
+      - ./docker/php/php.prod.ini:/usr/local/etc/php/conf.d/zzz-minty-dev.ini:ro
+    depends_on:
+      - db
+      - memcached
+    restart: unless-stopped
+
+  scheduler:
+    build:
+      context: .
+      dockerfile: docker/php/Dockerfile
+    env_file:
+      - .env
+    environment:
+      APP_ENV: prod
+      APP_DEBUG: "0"
+    volumes:
+      - ./:/var/www
+      - ./docker/php/php.prod.ini:/usr/local/etc/php/conf.d/zzz-minty-dev.ini:ro
+    depends_on:
+      - db
+      - memcached
+    command: sh -lc "while true; do php -d display_errors=0 bin/scheduler-run.php || true; sleep 60; done"
+    restart: unless-stopped
+
+  db:
+    image: mariadb:11.4
+    env_file:
+      - .env
+    environment:
+      MARIADB_ROOT_PASSWORD: ${DB_ROOT_PASSWORD}
+      MARIADB_DATABASE: ${DB_NAME}
+      MARIADB_USER: ${DB_USER}
+      MARIADB_PASSWORD: ${DB_PASS}
+    volumes:
+      - db_data:/var/lib/mysql
+      - ./db/init:/docker-entrypoint-initdb.d:ro
+    restart: unless-stopped
+
+  memcached:
+    image: memcached:1.6-alpine
+    restart: unless-stopped
+
+volumes:
+  db_data: