What problem does it solve? Planning a single phase of a multi-phase software roadmap is error-prone: interfaces drift between parallel workstreams, file ownership overlaps cause merge conflicts, and acceptance criteria end up untestable. This Skill produces a rigorously structured phase-plan document that freezes interfaces upfront and decomposes work into parallel-safe swim lanes with disjoint file ownership. ## Core Features & Use Cases - Architecture-first phase planning: Reads a versioned roadmap (e.g., specs/phase-plans-v1.md), resolves the target phase, and produces a plan document with interface freeze gates, a lane DAG, per-lane test/impl/verify tasks, and testable acceptance criteria. - Multi-agent consensus and external review: Optional --consensus mode runs 2-3 Plan teammates with distinct architectural framings, and --review-external runs Gemini and Codex CLI reviews of the draft plan. - Mechanical plan validation: Ships scripts/validate_plan_doc.py, a stdlib-only linter that checks required headings, frontmatter roadmap SHA-256, DAG acyclicity, disjoint owned-file globs, test-before-impl ordering, and interface traceability. - Use Case: Given specs/phase-plans-v1.md, run the planner on phase P3 to produce plans/phase-plan-v1-P3.md with frozen contracts and parallel lanes, then hand it to an execution skill that spawns one worktree-isolated teammate per lane. ## Quick Start Ask the AI to plan phase P3 of the roadmap in specs/phase-plans-v1.md with architectural consensus enabled.
