Agent Skills: ring:writing-plans

Writing a rolling-wave phased implementation plan from a spec before coding: a phase-epic-task hierarchy where Phase 1 is detailed into dispatch-ready tasks and later phases stay epic-level for elaboration during execution. Use when a multi-file feature needs decomposition; runs after ring:exploring-codebases or pre-dev gates, hands off to ring:executing-plans or ring:running-dev-cycle. Skip for single-file changes or spikes.