fix(logs): cap json-file log size on authentik/immich/mariadb

These three containers were writing multi-GB/day of unbounded logs
(authentik_server 3.5GB, immich-server 2.3GB, owncloud_mariadb 2.1GB),
a major contributor to a recent 100% disk-full incident. Daemon-wide
default (max-size 10m, max-file 3) was also added to
/etc/docker/daemon.json on valhalla, but that only covers newly
created containers going forward -- these three need the explicit
per-service override since they're long-running and won't be
recreated otherwise.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

stacks/owncloud/docker-compose.yml

@@ -48,6 +48,11 @@ services:
     environment:
       - MYSQL_DATABASE=owncloud
     command: ["--max-allowed-packet=128M", "--innodb-log-file-size=64M"]
+    logging:
+      driver: json-file
+      options:
+        max-size: "10m"
+        max-file: "3"
     healthcheck:
       # $$ defers expansion to container runtime (env_file supplies the value)
       test: ["CMD-SHELL", "mariadb-admin ping -u root --password=\"$$MYSQL_ROOT_PASSWORD\""]