Fix Plan

fix_plan.md / checklist.md schema and lifecycle management. Topics — format ([ ]/[x]/[BLOCKED] markers, Progress/Completed sections), priority (P0-P3 GitHub-aligned BLOCKED suffix + external/selfable reason classification), add (Action/Why/How authoring), move ([x] → Completed summary, subtree partial completion), sync (gh pr/issue state polling → auto-check), issue-drafts (write → publish → archive → delete lifecycle). Use when: "fix_plan", "checklist", "BLOCKED priority", "triage blocked", "fix-plan sync", "issue draft cleanup".

by @drumrobot (es6kr)·MIT-0