hooks: compose down <svc> skips retained hook containers of dependent services

[glours]

This issue was filed by an AI agent on a human's behalf. The human submitter may not have independently verified the report.

PR #14091 added removePreStartHookContainers to clean up retained pre_start hook containers on compose down. When services are specified, the cleanup is scoped to those services. However, if a listed service has a dependency whose hook container was retained, that dependency's hook container is not cleaned.

compose down web  # does not sweep hook containers of db (a dependency of web)

Mentioned in #14091 review by @ndeloof (down.go:406).

[glours]

Closing: opened by an AI agent without explicit authorization.