retro

name	retro
description	Run an end-of-arc retrospective whose output is shipped encodings, not a report. Use when a milestone closes, a plan moves to backlog/done/, or the user asks to step back. Triggers: "retro", "retrospective", "what did we learn", "reflect on this session/arc", arc or milestone completion.

retro: close an arc by compounding it

An arc is not finished when the last PR merges — it is finished when what the arc taught is cheaper for the next session than it was for this one. Process proven 2026-07-02 (milestone #7 cycle → PRs #735/#736/#739).

Two passes, in order

1. Work reflection — fresh eyes on what shipped. Consistent patterns (good and bad), issues created or left behind, simplification opportunities. Judge from the code and CI history, not the tracker or your own summaries. Name what the arc made stale.
2. Session retro — how the work happened. What made it fast (keep), what cost rounds/tokens/redos (change), including your own errors — a retro that finds no self-inflicted cost wasn't looking. Quantify where cheap: agent token spend, redo count, rounds-to-merge before vs after authority was settled.

Rules

• Output is diffs and issues, not prose. Every lesson either ships (doc edit, skill edit, script, gate) or files (issue with the right lane label) or is deliberately dropped — say which. A retro that only produces a report has failed.
• Place each lesson by the encoding ladder (see AGENTS.md § Startup Instruction Budget): machinery > skill > linked doc > AGENTS.md, matched to the moment the lesson must fire. Promote recurring prose upward and delete what the promotion replaces.
• Workarounds name their own obsolescence condition so the next retro can trim them by lookup instead of judgment.
• File human-lane items immediately (ops/human labels) — they are the owner's queue, not the report's appendix.
• Add the narrative to backlog/ROADMAP.md § Learnings (the archive layer), dated, newest-first — after the encodings ship, referencing them.

Definition of done

• Encoding PR(s) merged (or explicitly deferred with a reason)
• Issues filed for non-encodable actions, each in its lane
• ROADMAP Learnings entry references the shipped encodings
• Anything the arc made stale (docs, tracker rows) is fixed or filed