harness-drift-from-history

The natural ops question after running `oia-audit` weekly is "did anything drift?" Before this skill, the answer required a three-step sequence: ```bash npx ruflo metaharness audit-list --format json # → pick a key by hand npx ruflo metaharness oia-audit --format json > /tmp/curr.json npx ruflo metaharness audit-trend \ --baseline-key <picked-key> --current /tmp/curr.json \ --alert-on-distance-below 0.95 ``` This skill collapses it into one command: ```bash npx ruflo metaharness drift-from-history --threshold 0.95 ``` ## What it does 1. Lists records from `metaharness-audit` namespace via audit-list.mjs 2. Picks the most recent record by `startedAt` (or `--baseline-since 7d` skips anything newer than 7 days) 3. Runs a fresh `oia-audit` against the current path 4. Diffs the two via audit-trend, applying `--alert-on-distance-below ${threshold}` 5. Returns the structured drift report ## Architectural constraint inheritance (ADR-150) | Constraint | How drift-from-history satisfies it | |---|---| | Removable | Pure subprocess composition over existing scripts — no new `@metaharness/*` import | | Optional | If oia-audit reports `degraded:true`, this skill exits 3 with a degraded payload | | Graceful | Empty audit history → exit 2 with hint to seed it; never crashes | | CI-gate | Smoke step 17z16 anchors the dispatcher entry + subcommand listing | ## Exit codes - 0 — similarity ≥ threshold (or threshold not crossed) - 1 — drift detected: similarity < threshold (alert fired) - 2 — config error (no history, audit-list failed) - 3 — upstream metaharness absent (degraded payload returned) ## Example ```bash $ npx ruflo metaharness drift-from-history --threshold 0.95 # drift-from-history Baseline: audit-2026-06-16T22-58-47-840Z Current: 2026-06-16T23:05:02.231Z Structural similarity: 1 (near-identical) Distance: 0 ✓ similarity ≥ 0.95 — OK ``` ## Implementation [`scripts/drift-from-history.mjs`](../../scripts/drift-from-history.mjs)