The **ubborg‑lineage‑find‑common‑ancestor‑pmb‑js** package provides a single utility function that, given two “lineages” (arrays of parent objects, strings, or objects exposing a `traceParents` method), computes their lowest common ancestor, the shared prefix of the two lineages, and the remaining steps from that ancestor to each input. It’s aimed at developers who need to compare hierarchical structures—such as resource plans, organizational charts, or any parent‑child lists—to determine relationships and common ancestry in JavaScript/Node.js environments.