MySQL dependency

This fresh-install sample uses MySQL 8.4.11 LTS (previously 5.6). See the official image for supported tags. Run from the repository root:

kubectl create namespace database
kubectl apply -k contents/helm-vs-kustomize/dependencies/mysql
kubectl -n database rollout status deployment/mysql --timeout=300s
bash scripts/e2e/run.sh mysql

The startup/readiness probes authenticate as the sample user and query the sample database. E2E also verifies SQL writes and reads through mysql.database.svc. Credentials are for local training only and data is ephemeral. This is not an in-place upgrade procedure for an existing 5.6 database. The Flask examples are outside this test; older clients may need updates for MySQL 8.4 authentication.