v1.2

feat: add optional hetzner-np cluster target (#3)

Purely additive: new optional input kubeconfig_hetzner_np + a new
conditional k8s-set-context step for CLUSTER == 'hetzner-np'. Existing
np/pr paths are untouched.

Consumers opt in by setting cluster: hetzner-np in their envs.yaml and
passing kubeconfig_hetzner_np - everyone else's behavior is unchanged.

Do not retag the floating v1 with this - main is already ahead of v1 by
the helm v4.2.2 pin fix (unreleased to v1 consumers). Tag this as an
immutable v1.2 instead so editor-directus can reference it explicitly
without silently shipping the pending helm pin to every other v1 consumer.

Co-authored-by: Kacper Guzik <kacperguzik@MacBook-Air-Kacper.local>