ijfw-complete-milestone

Archive a completed milestone, capture what shipped, and surface the next milestone. Domain-agnostic -- a milestone may be a software release, a book part, a campaign wave, a design-system tier, or any other top-level project unit defined in `.planning/ROADMAP.md`. ## Inputs - Milestone identifier (e.g. `1.5.0`, `part-two`, `wave-3`). If the user did not name one, ask once: `Which milestone are we wrapping?` Accept any string that appears as a milestone heading in `.planning/ROADMAP.md`. ## Process 1. **Verify completion.** - Read `.planning/ROADMAP.md`. Find the milestone block for `<id>`. - List every phase under that milestone. For each phase, check that it is marked complete (e.g. `[x]`, `status: complete`, `shipped`, or has a `SUMMARY.md` in `.planning/<milestone>/<phase>/`). - If any phase is incomplete: surface the gap and ask `Proceed anyway and treat the open phase as deferred? (y / fix first)`. Do not auto-advance. 2. **Extract learnings (dispatch agent).** - Dispatch `ijfw-extract-learnings` with the milestone scope. The agent reads every `SUMMARY.md`, `RETRO.md`, and commit message in `.planning/<milestone>/**` and writes `.planning/<milestone>/LEARNINGS.md` (decisions, surprises, patterns, lessons). - If the agent is unavailable in this runtime, write a stub `LEARNINGS.md` with `_pending: dispatch ijfw-extract-learnings when available_` and surface the gap. 3. **Generate milestone summary (dispatch skill).** - Dispatch `ijfw-milestone-summ...