Parse a URI reference into components (regex from RFC 3986 appendix B, implemented directly).
Percent-decode a string (used on JSON Pointer fragments). Invalid escapes are left verbatim.
Remove "." and ".." path segments (RFC 3986 §5.2.4).
Resolve a URI reference against a base URI (RFC 3986 §5.2.2) and return the recomposed target string. The fragment of reference is preserved; the base's fragment never propagates.
Split a URI into its fragment-free part and the fragment ("" when none).
Decomposed URI reference (RFC 3986 §3). Empty-vs-absent matters for authority and query, so those carry presence flags.
RFC 3986 URI handling: parsing into components, reference resolution against a base URI (§5.2), and fragment splitting. Used for $id, $ref, $anchor, and $dynamicRef base-URI resolution.