fp-plan

Phase 2 of the feature-pipeline suite. Use this after /fp-explore has filed issues and printed the M1 stop hook — when you need to turn a set of filed GitHub issues into an approved implementation plan and a draft PR. Triggers on: "plan the fix", "create the branch and PR", "draft the implementation plan", "ready to plan", "fp-plan", "next step after explore", "convert issues to a plan", "plan phase". Reads issueNumbers from state, writes a Problem Statement, opens a feature branch + draft PR, spawns a HEAVIER sub-agent for the numbered plan, and blocks on explicit user approval before writing plan to state. Does NOT write any code — that is /fp-implement.