Verbessere Docker Compose Kompatibilität für Installation

- Verbessere Docker Compose Versionsprüfung und -installation
- Aktualisiere docker-compose.yml zu Version 3 Format
- Behebe YAML-Syntax-Fehler in Environment-Variablen
- Füge Unterstützung für beide Befehlsvarianten hinzu (docker-compose/docker compose)
- Verwende Docker Compose v2.6.1 für ARM-Architekturen (Raspberry Pi)

🤖 Generated with [Claude Code](https://claude.ai/code)

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

backend/docker-compose.yml

@@ -1,4 +1,4 @@
-version: '2'
+version: '3'
 
 services:
   backend:
@@ -10,7 +10,7 @@ services:
       - DATABASE_PATH=${DATABASE_PATH:-instance/myp.db}
       - TAPO_USERNAME=${TAPO_USERNAME:-till.tomczak@mercedes-benz.com}
       - TAPO_PASSWORD=${TAPO_PASSWORD:-744563017196A}
-      - PRINTERS='${PRINTERS:-{"Printer 1": {"ip": "192.168.0.100"}, "Printer 2": {"ip": "192.168.0.101"}, "Printer 3": {"ip": "192.168.0.102"}, "Printer 4": {"ip": "192.168.0.103"}, "Printer 5": {"ip": "192.168.0.104"}, "Printer 6": {"ip": "192.168.0.106"}}}'
+      - "PRINTERS=${PRINTERS:-{\"Printer 1\": {\"ip\": \"192.168.0.100\"}, \"Printer 2\": {\"ip\": \"192.168.0.101\"}, \"Printer 3\": {\"ip\": \"192.168.0.102\"}, \"Printer 4\": {\"ip\": \"192.168.0.103\"}, \"Printer 5\": {\"ip\": \"192.168.0.104\"}, \"Printer 6\": {\"ip\": \"192.168.0.106\"}}}"
       - FLASK_APP=app.py
       - PYTHONUNBUFFERED=1
     volumes: