institutional-memory-distill

# Distilling Institutional Memory (Trip-Wire) ## Overview Codebases accumulate decisions faster than anyone can remember them: "we tried Redis here and reverted it," "legal blocked this vendor once already," "the team already decided against a global feature flag and re-litigates it every few months." That reasoning usually lives — once — in a merged PR's description, a design doc's "Alternatives Considered" section, or a postmortem's root-cause writeup, and then it's gone. Nobody re-reads six-month-old PRs before starting new work, so the same rejected path gets proposed again, argued again, and sometimes shipped again before someone remembers why it didn't work last time. This skill is the **distillation half** of trip-wire: it reads a project's own PR history, design docs, and postmortems, and turns *decisions with reasoning* — not just decisions — into structured, queryable entries in the project's `decision_ledger`. The **query half** lives in `ult-context-generate/SKILL.md` Step 7.7, which checks every new context package's aspects against this ledger and surfaces a `revise`/`proceed`/`escalate` hit when something the ledger already knows about overlaps the new work. **Run this:** - Once, early in a project's life, to backfill the ledger from existing history - Again periodically, or on demand ("distill decisions from the last 20 merged PRs") — it is fully re-runnable; see "Idempotency" below **Output:** entries, cursors, tombstones, and (indirectly, via `ult-con...