daviaraujocc/lgtm-stack — reverse-engineered prompt

Build me a simple starter kit for running the Grafana LGTM observability stack on Kubernetes. I want someone to be able to clone the repo and run one Makefile command for a local cluster like minikube or k3s, then open Grafana and see logs, metrics, and traces flowing into Loki, Mimir, and Tempo.

Include a local setup that uses MinIO for storage, plus a GCP setup that creates or documents the needed buckets and service account permissions. Add clear Helm values and Kubernetes manifests for the stack, Promtail, Prometheus, and an OpenTelemetry Collector.

Please include a tiny Flask demo app that sends sample logs, traces, and metrics so I can prove the whole thing works. Write the README like a step by step guide with install, test, access Grafana, send data, troubleshoot, and uninstall sections. If chart details changed, look up the current Grafana docs online.