feat: update env.example with latest configuration

Changes:
- Rebrand: Secure Portal → SafeDocs Portal
- Add File Upload section (UPLOAD_DIR, MAX_FILE_SIZE, ALLOWED_FILE_TYPES)
- Add ClamAV configuration (CLAMAV_HOST, CLAMAV_PORT, CLAMAV_ENABLED)
- Add APP_VERSION comment (set automatically by Docker build)
- Update VERSION to 1.0.18

All required environment variables are now documented for
production deployments.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

env.example

@@ -1,5 +1,5 @@
 # ===========================================
-# Secure Portal - Environment Configuration
+# SafeDocs Portal - Environment Configuration
 # ===========================================
 # Kopieren nach .env und Werte anpassen:
 #   cp .env.example .env
@@ -39,7 +39,7 @@ CORS_ORIGIN=https://portal.example.com
 # Provider: brevo, sendgrid, smtp
 MAIL_PROVIDER=smtp
 MAIL_FROM_EMAIL=noreply@example.com
-MAIL_FROM_NAME=Secure Portal
+MAIL_FROM_NAME=SafeDocs Portal
 
 # Brevo (wenn MAIL_PROVIDER=brevo)
 BREVO_API_KEY=your_brevo_api_key_here
@@ -54,6 +54,19 @@ SMTP_USER=your_smtp_user
 SMTP_PASSWORD=your_smtp_password
 SMTP_SECURE=false
 
+# ----- File Upload -----
+# Upload-Verzeichnis (WICHTIG: muss /app/uploads sein für Docker!)
+UPLOAD_DIR=/app/uploads
+# Maximale Dateigröße
+MAX_FILE_SIZE=100MB
+# Erlaubte Dateitypen
+ALLOWED_FILE_TYPES=pdf,doc,docx,xls,xlsx,png,jpg,jpeg
+
+# ----- Virus Scanner (ClamAV) -----
+CLAMAV_HOST=clamav
+CLAMAV_PORT=3310
+CLAMAV_ENABLED=true
+
 # ----- Lizenzierung (optional) -----
 LICENSE_SERVER_URL=https://license.unixweb.de
 LICENSE_KEY=
@@ -62,5 +75,9 @@ LICENSE_KEY=
 # Registrierung deaktivieren nach Admin-Erstellung
 ENABLE_REGISTER=true
 
+# ----- Version (automatisch gesetzt bei Docker Build) -----
+# Wird vom Docker Build als Build-Arg übergeben
+# APP_VERSION=1.0.18
+
 # ----- Docker Registry Version (für docker-compose.registry.yml) -----
-VERSION=1.0.3
+VERSION=1.0.18