Switch app-of-apps, platform, apps, and previews ApplicationSets
to read from in-cluster Gitea (gitea-helm-ssh.platform.svc:2222).
Previews now use Gitea PR generator instead of GitHub.
Deploy Gitea via Helm with dedicated CloudNativePG database,
in-cluster Actions runner (DinD), and built-in container registry.
ArgoCD repoURLs updated to use in-cluster Gitea SSH. Preview
ApplicationSet switched from GitHub PR generator to Gitea PR
generator. App images now pull from gitea.coreworlds.io registry.
Remaining setup after deploy: seal runner token, ArgoCD API token,
and registry pull secret once Gitea is running. Add ArgoCD deploy
key to Gitea repo settings.
