Restart the server when its config changes (3.0.0+up2026.8.2.java8)

The StatefulSet now carries two annotations over its two configuration
sources, so a change to either produces a new pod template and a controlled
restart:

  checksum/config      the rendered ConfigMap (init.sh) - complete, Helm sees
                       the whole content
  checksum/secret-ref  the rendered OnePasswordItem - the op:// item path only,
                       because the Secret's content is materialized by the
                       operator and is unknown to Helm at render time

Two separate annotations rather than one combined hash: they carry different
guarantees, and a single number would blur "covers everything" and "covers the
path but not the content" into one value that nobody can interpret in a
kubectl describe.

The operator's own operator.1password.io/auto-restart is deliberately NOT set:
it restarts Deployments only. Verified in the operator source (main, 9c3b1b9):
restartWorkloadsWithUpdatedSecrets lists nothing but appsv1.DeploymentList and
getPodTemplate has a single case for *appsv1.Deployment. On this StatefulSet
the annotation would be inert while suggesting the opposite, so the remaining
gap - a rotated value inside the vault item - is documented in values.yaml
instead.

First of the three stage-3-style publishes, so the java8 line goes first and
main ends up on java21. Only the published Java line differs between them:
appVersion 2026.8.2-java8 and the matching minecraft.version default 1.12.2.

Major bump: runtime behaviour changes. A configuration change now costs a full
server restart - 124 s measured for ftb-skies on Longhorn.

Refs #82.

minecraft-server/Chart.yaml

@@ -13,8 +13,8 @@ type: application
 # continuously, so a pod restart could pull a different image than the last one
 # without anything being recorded anywhere. The dated tags are immutable, so the
 # image is now pinned by the chart version like every other chart in this repo.
-version: 2.0.0+up2026.8.2.java21
-appVersion: "2026.8.2-java21"
+version: 3.0.0+up2026.8.2.java8
+appVersion: "2026.8.2-java8"
 
 maintainers:
   - name: jklein