Cycle 0053 (multi-tap trace join on timestamp, #93) closes drift-clean.
Audit (architect drift review over 066638e..HEAD against docs/design + the
CLAUDE.md domain invariants):
- C8/C18 honoured: join_on_ts is a post-run reduction over recorded
(Timestamp, Vec<Scalar>) sink streams, a true sibling of summarize/f64_field
in the report layer — correct architectural home.
- C3 not violated: the join runs post-run over already-recorded output, not
in-graph; no as-of join smuggled into the DAG. C1 ts-uniqueness is a
documented precondition, not a runtime check — consistent with how the
engine leaves wiring-time invariants to contract.
- Option-per-side keeps the engine honest (reports presence; the consumer owns
the 0.0/-1/false defaults). The hand-rolled *_by_ts HashMaps are fully gone;
the two RED unit tests pin the #93 cardinality-misalignment + spine-drop.
- No drift, no debt, no ledger entry needs updating. Recommendation: carry on.
Regression gate: no dedicated regression scripts configured (optional per the
conventions); build/test/clippy --workspace --all-targets is the gate and ran
green — the gated GER40 byte-identity tests executed against the local archive
(not skipped), proving drain_trace's trace is byte-preserved across the
refactor.
Per the artifact lifecycle (committed while the cycle is live, git rm at cycle
close), the ephemeral spec and plan are retired here; their durable rationale
lives in the implementation commits 74324d1 / 35c5adc and the git history.
Brummel
7deb38edd8