What problem does it solve? Building a multi-stage agentic workflow platform requires coordinating runtime execution, definition versioning, evidence validation, owner resolution, action policies, and UI components without breaking existing behavior. This Skill provides a sequenced 12-PR implementation plan with architecture constraints, rollback strategies, and verification commands. ## Core Features & Use Cases - Sequenced PR Plan: Twelve incremental PRs covering runtime correctness, definition versioning, stage execution plans, evidence contracts, owner binding, action registry, pipelines, worktree environments, catalog, control panel UI, workflow studio, and self-improvement loops. - Architecture Constraints: Enforces rules such as workflow_execution as source of truth, pinned immutable definition versions, open workflow keys, and approved action registry for side effects. - Rollback and Verification: Each PR documents fallback behavior plus Go test and pnpm typecheck commands. - Use Case: A backend engineer implementing stage execution plans follows PR-02 to build the PlanBuilder with deterministic JSON snapshots and redacted agent task contracts. ## Quick Start Ask the agent to implement the next workflow platform PR following the workflow-implementation plan, starting with the runtime correctness baseline.