VictoriaLogs, like the VM scraper, is IPv4-only by default: ":9428" binds
0.0.0.0 only, so ns1/ns2 pushing journald over the IPv6 mesh got "connection
refused" while control's own loopback (v4) upload worked. Add -enableTCP6 so it
binds [::] (dual-stack), matching the flag already used for the scraper.
Also simplify the systemd-journal-upload override to just startLimitIntervalSec=0
(retry forever / self-heal) and drop the SuccessExitStatus masking: a persistent
sink failure should stay loud rather than be hidden behind a green deploy.
Berwn
9c8a2abf3f