Traversal API

Name	Summary	Notes & Examples
path	the path being validated or morphed	✅ array indices represented as numbers ⚠️ mutated during traversal - use `path.slice(0)` to snapshot 🔗 use propString for a stringified version
errors	ArkErrors that will be part of this traversal's finalized result	✅ will always be an empty array for a valid traversal
root	the original value being traversed
config	configuration for this traversal	✅ options can affect traversal results and error messages ✅ defaults < global config < scope config ✅ does not include options configured on individual types
reject	add an ArkError and return `false`	✅ useful for predicates like `.narrow`
mustBe	add an ArkError from a description and return `false`	✅ useful for predicates like `.narrow` 🔗 equivalent to reject ({ expected })
error	add and return an ArkError	✅ useful for morphs like `.pipe`
hasError	whether currentBranch (or the traversal root, outside a union) has one or more errors