arrstack/nzbget: fix nonexistent image tag v26.2 -> version-v26.2

The nzbget pod is stuck Init:ImagePullBackOff. The deployment pins
linuxserver/nzbget:v26.2 (both the seed-config initContainer and the
main container), but linuxserver never publishes a bare 'v26.2' tag:
the registry returns NotFound / manifest 404. linuxserver's version
pins for nzbget use the 'version-v<MAJOR>.<MINOR>' scheme.

Switch both images to version-v26.2, which resolves (manifest HTTP 200)
via the artifactapi dockerhub mirror and keeps nzbget on the 26.2 line.
Matches the version-pin convention used by the sibling sonarr/radarr
deployments. No other change; seed-config init logic already mirrors
linuxserver's own init (same /app/nzbget/share/nzbget/nzbget.conf
template copy) so it is unaffected.

apps/base/arrstack/nzbget/deployment.yaml

@@ -29,7 +29,7 @@ spec:
         # repeated option, and the grep guard keeps re-runs idempotent so admin
         # UI edits to the persisted /config/nzbget.conf survive restarts.
         - name: seed-config
-          image: artifactapi.k8s.syd1.au.unkin.net/dockerhub/linuxserver/nzbget:v26.2
+          image: artifactapi.k8s.syd1.au.unkin.net/dockerhub/linuxserver/nzbget:version-v26.2
           command:
             - sh
             - -c
@@ -81,7 +81,7 @@ spec:
               mountPath: /media/movies
       containers:
         - name: nzbget
-          image: artifactapi.k8s.syd1.au.unkin.net/dockerhub/linuxserver/nzbget:v26.2
+          image: artifactapi.k8s.syd1.au.unkin.net/dockerhub/linuxserver/nzbget:version-v26.2
           imagePullPolicy: IfNotPresent
           ports:
             - name: http