Resolves a $dynamicRef by checking if the static target has a matching $dynamicAnchor, then performing dynamic scope lookup through the scope stack. Falls back to static $ref resolution if no dynamic anchor is found.

Resolves and validates a static $ref.

Looks up the target schema in the compiled defs registry. If not found locally and the reference points to a remote URI, attempts to load it using the external_loader. Supports JSON Pointer references, anchor references, and absolute/relative URIs.