feat: add cpu_shares to mastercontainer and sibling containers

Weight CPU shares so the mastercontainer and core containers stay
responsive under heavy load from optional containers.

Signed-off-by: Simon L. <szaimen@e.mail.de>
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

develop.md

@@ -10,6 +10,7 @@ sudo docker run \
 --publish 80:80 \
 --publish 8080:8080 \
 --publish 8443:8443 \
+--cpu-shares 2048 \
 --volume nextcloud_aio_mastercontainer:/mnt/docker-aio-config \
 --volume /var/run/docker.sock:/var/run/docker.sock:ro \
 ghcr.io/nextcloud-releases/all-in-one:develop