hyperbuild-4-product-speclisted

# Step 4 — Product spec (the PRD) You are executing step 4 (product-spec) of the hyperbuild pipeline. Steps 2 ∥ 3 (run as the concurrent pair) filled the research vault with competitor dossiers and real-user sentiment, and step 3.5 — your immediate predecessor — adversarially audited their two synthesis docs, annotating weakened claims and moving refuted ones to `## Refuted by verification` sections (that exact heading — grep for it, not for any other wording); this step compresses the audited corpus into the single PRD that step 4.5 expands into per-feature specs and that steps 6–8 (design + mockups), 11 (epics), and 14 (implementation) all build from. **Goal:** write `research/product-spec.md` — personas, differentiators, a fully-traced MoSCoW feature list, and the canonical screen inventory — then have `hb-spec-critic` attack it and patch every finding via Edit. **Why this step exists:** everything downstream is derivative of this file. An untraced "must" here becomes a feature spec nobody asked for (4.5), three mockups of it (8), an epic of tasks for it (11), and days of implementation (14). Corrections applied here cost one Edit hunk; corrections applied after step 8 cost re-mocking three design systems. --- ## Inputs Read these before doing anything: - `runs/<run_tag>/idea.md` — the verbatim app idea. GOSPEL. - `runs/<run_tag>/manifest.json` — `run_tag`, `gear` (standard | premier), `platform`; confirm `steps["2"]`, `steps["3"]`, and `steps["3.5"]` are `done` - `