fix(nzbget): wait for gluetun tunnel before starting (prevents queue cancellation)

On pod start the nzbget container raced gluetun: /etc/resolv.conf points at
10.128.0.1 (reachable only via the WireGuard tunnel), so for the ~20s gluetun
needs to establish the tunnel every DNS lookup from nzbget returned EAI_AGAIN.
Any in-queue download that had articles fetched during that window dropped
below the HealthCheck threshold (~97.9%) and was auto-cancelled — even items
that would otherwise complete (saw 97.6-97.8% health = "very nearly fine").

Override the nzbget container's entrypoint to poll DNS resolution and only
exec /init once it succeeds. That's the direct test of "tunnel is up + DNS
works", which is what nzbget needs.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

custom_helm_charts/nzbget/templates/deployment.yaml

@@ -44,6 +44,10 @@ spec:
         - name: {{ .Chart.Name }}
           image: "{{ .Values.image.repository }}:{{ .Values.image.tag }}"
           imagePullPolicy: {{ .Values.image.pullPolicy }}
+          {{- with .Values.command }}
+          command:
+{{ toYaml . | indent 12 }}
+          {{- end }}
           env:
 {{ toYaml .Values.env | indent 12 }}
           ports: