tdd-authorlisted

# TDD authoring Run once after a PRD update. YOU decide how many TDDs to write, and their scope, based on what changed. Persist each to `docs/tdd/NNNN-<slug>.md`. ## Relationship to superpowers (read first) This skill IS the technical-design step for throughline — the governance-producing equivalent of `superpowers:writing-plans`. When the user invokes `/tdd-author`, do NOT also invoke `superpowers:brainstorming` or `writing-plans`; this skill owns the phase and its output is the TDD/ADR design-of-record (see [[ADR 0001]] in `docs/adr/`). If a `docs/superpowers/plans/*` (or `specs/*`) file or other prior design notes exist, READ and fold in their substance rather than redoing the work; they are transient input, never authoritative, never relocated. The canonical record is `docs/tdd/` + `docs/adr/`. A throughline TDD is a DESIGN, not a step-by-step build script — the bite-sized failing-test-first task breakdown is `/implement`'s job (`build-prompt.md`), so do not reproduce it here. ## 0. Resume check Source the draft helper: `source "${CLAUDE_PLUGIN_ROOT}/scripts/lib/drafts.sh"`. **If sourcing fails** (non-zero exit — the helper file is missing or broken), warn the user that draft persistence is unavailable and proceed in **degraded mode** WITHOUT it (the design pass still works; FR-46's recovery guarantees do not apply this run). Do not invoke any `tl_draft_*` function in degraded mode. Otherwise resolve the draft path once: `dpath="$(tl_draft_path tdd-author)"`. - If that