igor-gomes-u/electricity-price-gitops ? reverse-engineered prompt

Build me a GitOps repo for an app called Electricity Price Sweden that deploys to Kubernetes with Helm and Argo CD.

I want separate DEV, STAGING, and PROD environments, with the same container image digest promoted through them using pull requests, not rebuilds. The app code and image build should stay in a separate repo, and this repo should only handle deployment, promotion, and runtime config.

Please include validation for Kubernetes manifests, policy checks with OPA style rules, secret scanning, and basic guardrails so bad changes fail before merge. I also want observability setup for Prometheus, Grafana, and Alertmanager, plus the app metrics hooked up properly.

Make it work as a clean GitOps flow where Argo CD syncs each environment after merge, and include a rollback friendly setup through Git history. If you need to look up current docs or best practices for Argo CD, Helm, or Prometheus CRDs, go ahead and do that.