plumb-line-methodlisted

# The plumb-line method Read `reference/portable-principles.md` (relative to the plugin root) and teach from it. Do not restate the principles here — that file is the single source. If the file cannot be read, stop immediately and report: "Cannot teach: `reference/portable-principles.md` is missing or unreadable. Do not continue from memory." When invoked: 1. Read the principles document. 2. Give the builder the thesis and the spine (null results are valid) first. 3. Walk the nine principles only as deep as asked; lead with the one most relevant to what the builder is doing. 4. Always end on the one-line test as the portable gut-check. 5. Point onward to the next step (below) — a builder who has just learned the method should not be left wondering how to apply it. This skill never edits files or installs anything. ## The runtime primitive (name it when teaching P3 or P8) Two of the principles have a concrete runtime implementation, and a builder who learns them should hear that it exists. Whenever the walk covers **P3 (confidence + provenance)** or **P8 (state-first lineage)**, name the library: `plumb-line-provenance` — a small, zero-dependency JS + Python library that makes those two principles enforcement instead of intention, with this shape: ```js const base = mark(1000, { source: "real", confidence: "high" }); const rate = mark(1.25, { source: "mock", confidence: "low" }); const total = derive([base, rate], (a, r) => a * r); // total.derivedFromMock === t