Function is_owned_endpoint 

pub fn is_owned_endpoint(socket: &Path) -> bool

Whether socket belongs to a live task owner created by this user.

Provenance is structural, matching how the supervisor creates the endpoint: a Unix socket named OWNER_SOCKET_FILE directly inside a directory that is prefixed OWNER_DIRECTORY_PREFIX, owned by the current user, granted owner-only permissions, and located under the system temp root. Every part must hold, so a path the supervisor could not have produced is rejected.

Exposed so the binary-owned supervisor can assert that the endpoint it publishes satisfies the launcher’s provenance contract.