new-estimator

name	new-estimator
description	Scaffold a new ICC estimator with its estimand block, test skeleton, and oracle checklist. Use when adding a new ICC variant (e.g. consistency, one-way, multilevel).
allowed-tools	Read, Grep, Glob, Edit, Write

Instructions

Scaffold a new estimator without leaving it un-oracled (refuse otherwise — PRINCIPLES.md #1). Produce, in order:

1. Estimand block first (PRINCIPLES.md #2, before any code): a short spec naming the population quantity — which variance components are in the numerator/denominator, single vs. average, agreement vs. consistency, fixed vs. random raters, and the identifiability conditions. Follow the pattern in project/estimand-specs/. Represent the ICC as (signal component, {error component set}, averaging divisor) so variants are choices of the error set and divisor, not new code paths.
2. Function stub in R/ with roxygen including the "Which ICC is this, and when should you use it?" note and the key tradeoff (PRINCIPLES.md #13), cli messaging and classed errors via the abort_*() layer (PRINCIPLES.md #8).
3. Test skeleton in tests/testthat/ with the required oracle checklist (≥2 independent types): textbook/analytic, established package, seeded simulation. The oracle plan lives in the estimand-spec (its oracle-set section); register a row in project/REFERENCES.md only once the oracle is asserted green, naming the test file and provenance (ADR-015 single-source — REFERENCES holds no "planned" state; PRINCIPLES.md #4).
4. A project/DECISIONS.md stub if the estimator involves a modeling choice.

Add the task to the active milestone's board in project/MILESTONES.md (ADR-015; there is no separate TASKS.md). Do not implement the numerics until the estimand and oracle plan are written.