Update all ArgoCD Application references to use Gitea (github0213.com)
instead of GitHub for K3S-HOME/applications repository.
Also update docusaurus to use gitea-creds for Image Updater write-back.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Add application.yaml for ArgoCD self-registration
- Update kustomization.yaml to include application.yaml
- Set prune: false to prevent cascade deletion