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>

.env.prod.example

@@ -0,0 +1,35 @@
+APP_NAME=IMVS
+APP_URL=https://example.com
+APP_ENV=prod
+APP_DEBUG=false
+APP_TIMEZONE=Europe/Berlin
+APP_STORAGE_PATH=./storage
+APP_LOCALE=de
+APP_LOCALES=de,en
+APP_I18N_DOMAIN=default
+APP_CRYPTO_KEY=replace-with-64-char-hex-or-base64-key
+SESSION_NAME=IMVS
+TENANT_SCOPE_STRICT=true
+
+DB_HOST=db
+DB_PORT=3306
+DB_NAME=imvs
+DB_USER=imvs
+DB_PASS=replace-db-password
+DB_ROOT_PASSWORD=replace-db-root-password
+
+CACHE_SERVERS=memcached:11211
+
+FIREWALL_CONCURRENCY=10
+FIREWALL_SPINLOCK_SECONDS=0.15
+FIREWALL_INTERVAL_SECONDS=300
+FIREWALL_CACHE_PREFIX=fw_concurrency_
+FIREWALL_REVERSE_PROXY=false
+
+SMTP_HOST=
+SMTP_PORT=587
+SMTP_USER=
+SMTP_PASS=
+SMTP_FROM=
+SMTP_FROM_NAME=IMVS
+SMTP_SECURE=tls