Add OCI chart registry and cleanup resources upon release deletion

[hmoazzem]

Preflight Checklist

• I could not find a solution in the existing issues, docs, nor discussions
• I have joined the ZITADEL chat

Describe your problem

This may not be as important, but should be some enhancements. We're building a Supabase-like nocode backend particularly for Kubernetes, and it feels a bit odd to use

1. Make the chart available via OCI registry

  auth:
    zitadel:
      release:
        chartURL: registry-1.docker.io/edgeflare/zitadel:8.12.0 # shouldn't look registry-1.docker.io/zitadel/zitadel:8.12.0?

2. Add a values.schema.json

3. Some resources aren't deleted upon chart un-installation. Apparently, below resources need manual deletion

kubectl delete cm zitadel-config-yaml
kubectl delete secret zitadel-admin-sa
kubectl delete jobs.batch example-zitadel-init example-zitadel-setup

Maybe leaving these is intentional?

Describe your ideal solution

I mostly follow bitnami/charts for patterns, best-practices etc. In any case, if you think it's useful, I can pick some of the tasks too.

Version

8.12.0

App version

v2.70.0

Additional Context

No response