devPTIpack

Build a new devPTIpack function test-first — ask contract questions via AskUserQuestion, write failing tests (RED), then implement via Codex (GREEN).

Scaffold a Tier-1 testthat test file for a permanent (non-legacy) devPTIpack function per arch-03/arch-02.01 — uses bundled fixtures (ukr_shp, ukr_mtdt_full) and the helper-test-data.R harness, pins known behavioural quirks instead of skipping them.