// Package policyutil contains pure functions that transform compiled
// policy rules for a specific node. The headline function is
// [ReduceFilterRules], which filters global rules down to those relevant
// to one node.
//
// A node's [types.NodeView.SubnetRoutes] (approved, non-exit) participate
// in rule matching so subnet routers receive filter rules for
// destinations their subnets cover.
package policyutil