idea-lineage - Single-Idea Evolution Through the Brain

Convention: see conventions/quality.md for citation rules, quote fidelity, and source-backed claims.

Boundary: see docs/takes-vs-facts.md for the distinction between holder-attributed takes and the brain owner's hot facts. Do not collapse those layers when summarizing lineage.

What this solves

Users often want to understand how one idea changed across time: when it first appeared, when it became sharp, what it displaced, what it contradicted, and what version is alive now. That is different from building a whole concept map and different from charting an entity's metric trajectory.

Use this skill when the user asks about one idea, topic, phrase, or concept page and wants its evolution through the brain.