// Package traverse implements the core DNS traversal engine for ExploreDNS.
//
// The traversal engine starts from the DNS root servers and iteratively
// follows every referral it receives, building a complete picture of the
// delegation path for a domain.  Unlike a standard recursive resolver, which
// stops at the first authoritative answer, the traversal engine explores every
// branch so that delegation mismatches, lame delegations, or split authorities
// are all visible in the output.
//
// # Architecture
//
// A Traverser maintains a stack of Referral objects.  Each Referral
// represents a pending query to a specific set of nameservers for a specific
// name and record type.  The engine pops referrals one at a time, sends the
// query, classifies the response, and pushes any child referrals back onto the
// stack.
//
// When a referral contains nameserver names but no glue records (IP addresses),
// the engine resolves them via a secondary traversal before continuing.
//
// # Caching
//
// An InfoCache stores discovered glue records.  In fast mode (default) a
// single root cache is shared across all branches so that glue discovered in
// one branch is immediately available to sibling branches.  Disable fast mode
// (TraverserConfig.Fast = false) for fully independent branch resolution.
package traverse