3-lineage scrum on 434f466..0d4f033 surfaced one convergent finding
(Opus + Kimi) and 3 Opus-only real bugs. All actioned in this
commit. Two false positives (Kimi rollback misreading, Opus stale-
comment claim) verified + rejected — both required manual control-
flow inspection to refute, matching the documented Kimi-truncation
behavior in feedback_cross_lineage_review.md.
Convergent fix — DecodeIndex lost nil-meta items:
- Envelope version bumped 1 → 2.
- New v2 field: IDs []string carries the canonical ID set
explicitly, independent of meta map's nil-vs-{} sparseness.
- DecodeIndex accepts both versions: v2 reads from env.IDs; v1
falls back to meta-key inference (with the documented
limitation that nil-meta items are invisible — preserved for
backward-compat with already-persisted indexes).
- Encode emits v2 going forward.
- 2 new regression tests:
- TestEncodeDecode_NilMetaItemsSurviveRoundTrip: items added
with nil metadata MUST survive Encode → Decode and remain
visible to IDs(). Pre-fix would have yielded IDs() == [].
- TestDecodeIndex_V1BackwardCompat: hand-crafted v1 envelope
still decodes (proves the fallback path).
Opus-only fixes:
- handleMerge: non-ErrIndexNotFound errors at h.reg.Get(name) /
h.reg.Get(req.Dest) now return 500 + log instead of falling
through with nil src/dest pointers (which would panic on the
next deref). Real bug — only the sentinel error was handled.
- internal/drift/drift.go: mathLog wrapper removed; math.Log
inlined. Wrapper added no value (math was already imported).
- internal/distillation/audit_baseline.go: BuildAuditDriftTable's
bubble sort replaced with sort.Slice. Idiomatic + shorter.
Rejected after verification:
- Kimi WARN "missing rollback on partial merge": misread the
control flow. Code at cmd/vectord/main.go:404-414 does NOT
delete from src when dest.Add fails (continue before reaching
src.Delete). Only successful Adds trigger Deletes.
- Opus INFO "TimestampUnixNano comment references missing field":
field exists at scripts/multi_coord_stress/main.go:128. Opus
saw only the diff context, not the full file.
Deferred (no fired trigger):
- Opus WARN "no per-index lock during merge": no concurrent merge
callers today (operators run merge as deliberate one-shot job).
Worth a lock if/when matrixd or chatd start auto-triggering.
Disposition: reports/scrum/_evidence/2026-05-01/verdicts/post_role_gate_v1_disposition.md.
Build + vet + tests green; 2 new regression tests + all prior tests
unchanged.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
The original OPEN #2 line called for "SFT export pipeline +
audit_baselines lineage." Commit 7bb432f shipped the SFT export.
This commit ports the audit_baselines half — the longitudinal
drift signal that distinguishes "metrics shifted because the world
changed" from "metrics shifted because we broke something."
Mirrors Rust scripts/distillation/audit_full.ts's substrate:
- LoadLastBaseline(path) reads the most recent entry from
data/_kb/audit_baselines.jsonl. Returns (nil, nil) on missing
file (first run), errors on truncated last line (partial-write
detection — operators don't lose drift signal silently).
- AppendBaseline(path, baseline) appends one entry as a JSON line.
Atomic at the line level via bufio + O_APPEND. Creates the
parent directory if missing.
- BuildAuditDriftTable(prior, current, threshold) computes
per-metric drift. flag values mirror Rust exactly: first_run,
ok, warn. DefaultDriftWarnThreshold = 0.20 = Rust's 20%.
- FormatAuditDriftTable renders a fixed-width text grid for
stdout dumps in audit-full runs.
Edge cases handled:
- Zero-baseline: prior=0 means no division — PctChange stays nil.
current=0 → ok (no change). current>0 → warn (zero→nonzero is
always notable, never silently fine).
- New metric in current: flagged first_run, not "0%-change".
Operators see "this is a new signal we haven't tracked before."
- Sort: stable by metric name for deterministic JSON output and
clean CI diffs.
Generic on metric name (vs Rust's pinned p2_evidence_rows etc.):
the Rust phase numbering doesn't translate to Go directly. The
AuditBaselineRustCompat constant pins the Rust names so operators
running both runtimes use the same labels, which makes drift
comparison meaningful across the two pipelines.
13 new tests covering: missing file, last-line-wins, blank-line
tolerance, malformed-line errors, append round-trip, append-to-
existing, schema validation, first-run, threshold boundary,
zero-baseline, new-metric-in-current, sort-by-metric stability,
formatter output rendering.
OPEN #2's "audit_baselines lineage" half now closed. The
distillation package surface is at parity with the Rust pipeline:
scorer, scored runs, SFT export, audit baselines all available
on the Go side.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
root