plan-init

Create a structured project plan document for a task — the current planning suite. Interviews the user to fill gaps, explores the codebase, then produces a master plan.md stamped with the Format: v2 marker and a Suite row, and — when the plan lives under plans/ — registers it in the plans/README.md discovery index. Stays breakdown-unaware (work breakdown is /plan-phase's job) and adds UI-verification success criteria when UI is in scope. Use when the user invokes /plan-init, or says "make a plan", "create a plan", "plan this out", "let's plan before we start".