- cache_from/cache_to must be plain strings, not YAML lists — the
plugin-docker-buildx treats them as single string values and the
Woodpecker settings layer was splitting comma-separated list items
into separate --cache-from flags (type=registry and ref=... separately)
- caretta.tf: replace deprecated set{} blocks with values=[yamlencode()]
to fix Terraform plan error with newer Helm provider
