Files
Aura/crates/aura-engine
Brummel e5d80959e0 test: M×N×K stress matrix — node fan-out, deep chains, wide layers
The milestone's green end-to-end gate (#3): prove the closed
bootstrap + run substrate carries arbitrary node-level
fan-out / fan-in / depth / width DAGs deterministically (C1) and computes
every recorded stream correctly. Closes the two coverage holes the engine
tests left open after cycle 0006 — node fan-out (one PRODUCING node read
by several consumers; prior coverage was source fan-out only) and
deep-chain / wide-layer topologies.

Six tests appended to harness.rs's test module, composing the existing
Sma / Sub / Recorder / BarrierSum fixtures (no new fixtures, no aura-std
surface — C9):
- node_fan_out_identical_taps_record_identical_streams
- node_fan_out_divergent_consumers_each_compute_their_own
- node_fan_out_under_mixed_firing_each_consumer_records_per_policy
- deep_transform_chain_propagates_end_to_end
- wide_parallel_layer_multi_sink_records_each_stream
- milestone_end_to_end_mixed_dag_records_every_stream_deterministically

Each asserts exact (Timestamp, Vec<Scalar>) recorded values (hand-computed
from the SMA/Sub + firing/warm-up semantics) AND determinism via a second
fresh-harness drain proving bit-identical streams. 28 engine tests green
(22 + 6), clippy -D warnings clean. No engine misbehaviour surfaced.

closes #3
2026-06-04 14:59:13 +02:00
..