mongod's oplog size flag is --oplogSize on the command line

--oplogSizeMB is the configuration file's key (replication.oplogSizeMB); mongod refuses it as a flag, so setup.sh's
replica-set step left the unit restarting until the flag was fixed on Max.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LsXgEaXee4GCU1hwYgPJXw

deploy/systemd/privapub-mongod.service

@@ -7,7 +7,7 @@ Type=exec
 User=www-data
 Group=www-data
 # a one-member replica set (rs0), so a backup reads every collection at one instant; its oplog kept small
-ExecStart=/usr/bin/mongod --dbpath /var/lib/privapub/mongo --port 27022 --bind_ip 127.0.0.1 --noauth --wiredTigerCacheSizeGB 0.25 --replSet rs0 --oplogSizeMB 990 --quiet
+ExecStart=/usr/bin/mongod --dbpath /var/lib/privapub/mongo --port 27022 --bind_ip 127.0.0.1 --noauth --wiredTigerCacheSizeGB 0.25 --replSet rs0 --oplogSize 990 --quiet
 Restart=always
 RestartSec=5
 LimitNOFILE=64000