cairn-resync

name	cairn-resync
description	Operator-initiated re-discovery — resolve config drift, re-cluster topics, re-curate grown areas into DEC/INV drafts.
when_to_use	Use when the operator asks to "resync", "re-discover", "re-curate", or catch Cairn's ground state up to a grown/restructured tree — typically after the config-drift baseline nudge ("your project grew"). Three opt-in passes: deterministic config-resync, LLM topic re-cluster, and subagent re-curation of a new area into DEC/INV drafts. Skip during an active task, or when the operator only wants the one-tap config fix (that's `cairn_resync` direct, no skill needed).
allowed-tools	Skill(cairn:cairn-attention), Task(curator-map), Task(curator-reduce), Bash, Read

Skill: cairn-resync

Host portability

This skill is shared by Claude Code, Cursor, and Codex. Resolve Cairn MCP tools with the host's native discovery mechanism and use its structured question UI, falling back to a concise A/B/C chat question. Named curator briefs live under ../../agents/; dispatch them natively after reading the brief, or execute inline only when the host has no subagent capability.

You are running Cairn's operator-initiated re-discovery so committed ground state catches up to a tree that has grown or been restructured since adoption.

Everything here is opt-in, recoverable, and never auto-applies to committed ground: deterministic edits are review-class (the operator commits the diff); LLM passes spend the fast tier only on genuinely-new prose; re-curation produces _inbox/ drafts the operator drains. Confirm scope with the operator before any pass that spends model quota (re-cluster, re-curate).

Pass 1 — config-resync (deterministic, free)

Resolve the config-drift the sensor surfaced.

1. Preview: cairn_resync({}) (dry-run default). Summarize the proposed .cairn/config.yaml edits — add a grown dir to componentDirs, add a new file type to extensions, add a .gitignore entry to off_limits, drop a dead componentDir, re-point a moved entity's source_file.
2. On the operator's OK: cairn_resync({ apply: true }). It archives the pre-resync config.yaml to .cairn/ground/.archive/ and is idempotent. Tell the operator to review + commit the diff.
3. Pass area to scope either call to one subtree.

Pass 2 — topic re-cluster (LLM, opt-in)

Offer this when prose has moved/grown enough that the topic-index is stale. Confirm first — it spends the fast tier (only on new prose; unchanged pairs hit the cache).

1. Preview: cairn_resync({ recluster: true }) — re-walks + judges and reports topics_before → topics_after + judge_calls_fresh, but overwrites no map.
2. On OK: cairn_resync({ recluster: true, apply: true }) — archives the prior topic-index.yaml + anchor-map.yaml, then rebuilds them. The maps are gitignored, per-clone derived state, so there's nothing to commit.

Pass 3 — re-curation of a new area (subagents, opt-in)

Re-run the curator over a grown area and surface the result as DEC/INV drafts. Always scope to an area — a full re-curate is the adoption pipeline's job, not this. Confirm the area + the model spend first.

Ghost mode: if the repo is registered ghost, the curator dir is out-of-repo. The recurate:'walk' response returns the absolute curator_dir; give the subagents absolute paths under it (mirror cairn-adopt Step 3.5's path-resolution note).

3.1 — walk the area

Call cairn_resync({ recurate: "walk", area: "<dir>" }). It builds the curator corpus + shards scoped to that subtree and returns shards_path, curator_dir, records_total, and shards. If shards === 0, there's no curatable prose in the area — tell the operator and stop (skip emit).

3.2 — dispatch curator-map (parallel rounds of 4)

Read the shard plan with node (portable — never cat/jq):

node -e "console.log(require('node:fs').readFileSync(process.argv[1],'utf8'))" <shards_path>

For each shard, compose a curator-map Task brief with shard_id, the absolute shard_path (<curator_dir>/shards/<shard_file>), the absolute candidates_path (<curator_dir>/candidates/<shard_id>.jsonl), module, and project_domain. (Post-adoption the mapper's key_modules summaries may be gone — pass an empty module_flags and a short generic module_summary; the curation degrades gracefully.) Send up to four briefs per assistant message so they run in parallel; await each round before the next. Subagents write JSONL to disk and return a short summary — read disk, not the return text.

3.3 — dispatch curator-reduce

Once every candidates/<shard_id>.jsonl exists, spawn one curator-reduce subagent with the candidates_glob, the absolute final_path (<curator_dir>/final.jsonl), and project_domain. It synthesizes the de-duplicated DEC/INV set into final.jsonl.

3.4 — emit drafts

Call cairn_resync({ recurate: "emit" }). It validates each final.jsonl entry and writes it as a reviewable draft — DEC → .cairn/ground/decisions/_inbox/<id>.draft.md, INV → .cairn/ground/invariants/_inbox/<id>.draft.md, each status: draft. It rebuilds no ledger and graduates nothing. Report the dec_drafts + inv_drafts counts.

3.5 — hand off to cairn-attention

Invoke Skill(cairn:cairn-attention) so the operator drains the fresh drafts inline: accept graduates a DEC to the ledger / an INV to active; reject archives a .rejected.md tombstone; edit returns the body. Nothing the curator proposed touches committed ground until the operator accepts.