I need a small Helm-based workflow that handles Kubernetes image-pull secrets for workloads hosted in Docker Hub. The chart should be able to create a brand-new secret when none exists and also detect, patch, or replace an existing secret if I supply one—essentially both creating and managing the secret lifecycle. Updates will be triggered manually, so no periodic rotation logic is required; I simply want a reliable set of templates and README instructions that I can run with a single helm upgrade to refresh credentials whenever I choose. Please deliver: • Helm chart (Helm 3 format) with values.yaml supporting username, password, and optional e-mail • Templates for kubernetes.io/dockerconfigjson secret and an imagePullSecrets reference that can be toggled on/off per deployment • Clear, testable README showing helm install / upgrade commands and how to override values The solution must work against a standard upstream Kubernetes cluster using kubectl and be ready to drop into my existing Git repository.