refactor: extract shared print payload builder and skip-state reset

The print/start payload was duplicated in three places (upload path,
KX store, Moonraker API) and had drifted: the settings-based
vibration_compensation value was missing in the upload path. All three
paths now use _build_print_payload() and _reset_skip_state().

docker-compose.yml

@@ -10,6 +10,8 @@ services:
       - ./.env:/app/.env:ro
     ports:
       - "7125-7130:7125-7130"
+    # environment:
+    #   - BRIDGE_HOST_IP=192.168.1.100   # LAN-IP des Docker-Hosts (für korrekte Log-Anzeige)
     restart: unless-stopped
     logging:
       driver: json-file