Function handler_execution_order 

pub fn handler_execution_order(
    groups: &HashMap<String, Vec<RuleMatch>>,
    registry: &HashMap<String, Box<dyn Handler + '_>>,
) -> Vec<String>

Returns handler names in execution order.

Order is driven by each handler’s ExecutionPhase (see crate::handlers::ExecutionPhase for the full phase list and why each slot is where it is). The phase enum’s declaration order is the execution order — Provision → Setup → PathExport → ShellInit → Link.

Handler names not present in the registry are placed last in alphabetical order (they get ignored by the pipeline anyway).