Phase 4 of the Stratification milestone. aura-std held four C28 ladder
layers in one roster; this cuts them into layer-aligned, aura-core-only
node crates so the import direction is enforced by the crate graph:
- aura-std — engine nodes only (arithmetic/logic/rolling + sinks)
- aura-market — session, resample
- aura-strategy — bias, stops, sizer, cost-model machinery
- aura-backtest — sim_broker, position_management
- aura-vocabulary — the relocated closed std_vocabulary roster
Node modules move verbatim (byte-identical renames); consumers are
rewired by import path only. A new structural test
(aura-vocabulary/tests/c28_layering.rs) asserts each node crate's
[dependencies] stay within its C28-permitted inner set, catching the
acyclic-but-outward violation the compiler misses.
Behaviour byte-identical: full workspace suite green (1448 tests), no
golden edited, clippy -D warnings clean. C28 Status block updated.
closes#288
Second half of the #281 clock-enable set. CumSum is the generic
run-length accumulator with O(1) Neumaier-compensated state — the
branching Neumaier variant, not Sma's plain Kahan, so it stays exact
when a large running total absorbs a tiny sample (the standalone
accumulator has no windowed-magnitude guarantee; module doc explains
why the helper is not reused). When is the clock-enable driver: forwards
value iff gate, else a quiet cycle (eval->None), so every stateful
reducer composes gated unmodified — SMA(When(x,g),N) is the gated SMA.
Rosters CumSum and When (both count pins 31->33) and ships two engine
E2E fixtures: When forwarding/quiet-downstream through the real
GraphBuilder->compile->run seam, and a quiet When leg suppressing a
whole Resample Barrier(0) group (the deliberate stall semantics).
refs #281
claude