Function resolve_order 

pub fn resolve_order(
    resources: &[ResourceDefinition],
    tracker_names: &BTreeSet<String>,
) -> (Vec<String>, Vec<GraphProblem>)

Order resources so dependencies come before dependents. Dependencies may name trackers (which only need to exist) or other resources.

Never fails: an unresolvable dependency is skipped and reported, so a half-built graph still loads. Commands that act on the graph must check the reported problems first; commands that build it may proceed and warn.