kubernetes:4353.vb_47977da_9417 requires kubernetes-client-api >=
7.3.1-256.v788a_0b_787114 (confirmed via plugins.jenkins.io), but that
plugin was never explicitly pinned in installPlugins — left to
resolve on its own at image-build time, it landed on an older,
incompatible version. Every build agent launch then crashed with
NoSuchMethodError: ConfigBuilder.withMasterUrl(String) inside
Reaper.preLaunch -> KubernetesCloud.connect ->
KubernetesFactoryAdapter.createClient: pods provisioned fine at the
Kubernetes API level, but the controller could never actually connect
an agent to them, so every demo-go-app build hung forever at "Still
waiting to schedule task".
demo-go-app moved from ArgoCD's default project to the new webapp
project (devops-argo-config#7de2f8b). ArgoCD RBAC is keyed
<project>/<app-name>, so the jenkins-ci sync/get policy has to move
with it or syncArgoApp's scoped token starts getting silent 403s on
its next sync.
Adds accounts.jenkins-ci (apiKey) and a repo-scoped RBAC policy
(sync/get on default/demo-go-app only) so devops-lib's syncArgoApp
stage can trigger syncs without full admin access.