spec-tdd-coveragelisted

# spec-tdd-coverage **REQUIRED BACKGROUND:** Understand `spec-tdd` first. This is spec-tdd with a coverage discipline layered on — it inherits the two-tier agent-boundary split, "must be RED first," and Phase-3 don't-trust-self-report. Only read this when you already know spec-tdd. ## Overview spec-tdd, plus: the subagent **declares a case-list BEFORE implementing** and **reports per-class branch coverage after**; the orchestrator **gap-checks** the case-list against the impl's real branches. **Core principle: coverage must be measured and reported evidence — never a hopeful side-effect of green tests.** ## The gap this closes spec-tdd's handoff says *"add your own unit tests"* — no case-list, no coverage report. Observed baseline: a diligent subagent wrote **18 green tests and hit 100% branch coverage, yet reported none of it.** Coverage was *luck*, not *evidence*, and the orchestrator had no case-list to audit. A less-diligent subagent on a branchier function leaves holes with nobody the wiser — spec-tdd Phase 3 audits only the acceptance test, so unit coverage is a blind spot. ## Pre-flight — orchestrator tier check (I21) Before any work, check the model THIS session runs as. A run's judgment — the test/spec, the verification, the failure routing — executes entirely in the orchestrator's own context; I19 pins every dispatch tier, but nothing can upgrade the session itself. **Top tier in use, or no higher tier exists → silent, move on.** Otherwise surface this ONE a