refactor: split aura-analysis into statistics and backtest metrics

C28 phase 5 (Stratification): the backtest reductions - RunMetrics, RMetrics,
summarize_r, r_metrics_from_rs, and the position-event table - move verbatim
into aura-backtest::metrics, beside the position_management producer whose
record layout they read (the r_col/cost_col lockstep contract is now
intra-crate; its stale "aura-std" comment corrected). aura-analysis is reduced
to the domain-free half: the multiple-comparison hurdle math (inv_norm_cdf,
expected_max_of_normals) and the selection-provenance types
(FamilySelection/SelectionMode - kept beside the statistics so
RunManifest.selection embeds a foundation-grade type), [dependencies] = serde
only.

The engine re-export surface is name-unchanged (report.rs re-imports from both
crates), so no indirect consumer needed a source edit; aura-backtest moves from
aura-engine's dev-dependencies into [dependencies] as a commented TRANSIENT
widening of the C28 violation, removed by the phase-2 edge cut on this branch.
The campaign drift guard imports its pinned types from their new source
crates. Behaviour-preserving: 1448/0 tests, clippy -D warnings clean, serde
shapes byte-identical (C18), moved code traceable via git copy detection.

closes #291

Cargo.lock

@@ -100,9 +100,7 @@ dependencies = [
 name = "aura-analysis"
 version = "0.1.0"
 dependencies = [
- "aura-core",
  "serde",
- "serde_json",
 ]
 
 [[package]]
@@ -110,6 +108,8 @@ name = "aura-backtest"
 version = "0.1.0"
 dependencies = [
  "aura-core",
+ "serde",
+ "serde_json",
 ]
 
 [[package]]
@@ -133,6 +133,7 @@ name = "aura-campaign"
 version = "0.1.0"
 dependencies = [
  "aura-analysis",
+ "aura-backtest",
  "aura-core",
  "aura-engine",
  "aura-registry",

crates/aura-analysis/Cargo.toml

@@ -6,15 +6,8 @@ license.workspace = true
 publish.workspace = true
 
 [dependencies]
-aura-core = { path = "../aura-core" }
+# serde gives the selection-provenance types (`FamilySelection`/`SelectionMode`,
-# serde is admitted under the amended C16 per-case dependency policy (INDEX.md):
+# embedded by the engine's `RunManifest.selection`) their typed
-# it gives the run-report types a typed (de)serialization path for the run
+# (de)serialization path for the run registry (C18). Deterministic output
-# registry (cycle 0029). serde's output is deterministic (C1-safe).
+# (C1-safe). The backtest metric types moved to aura-backtest (#291).
 serde = { workspace = true }
-
-[dev-dependencies]
-# serde_json is used only by this crate's round-trip tests (the production types
-# derive serde, but JSON rendering lives in aura-engine's RunReport::to_json).
-# Test-only -> dev-dependencies, so it never enters the frozen artifact's library
-# link (C16 frozen-artifact scrutiny).
-serde_json = { workspace = true }

crates/aura-backtest/Cargo.toml

@@ -7,3 +7,13 @@ publish.workspace = true
 
 [dependencies]
 aura-core = { path = "../aura-core" }
+# serde gives the backtest metric types (`RunMetrics`/`RMetrics`/`PositionEvent`)
+# their typed (de)serialization path for the run registry (C18; moved with the
+# types from aura-analysis, #291). Deterministic output (C1-safe).
+serde = { workspace = true }
+
+[dev-dependencies]
+# serde_json is used only by the moved metric round-trip tests (JSON rendering
+# for production lives in aura-engine's RunReport::to_json). Test-only, so it
+# never enters the frozen artifact's library link (C16).
+serde_json = { workspace = true }

crates/aura-backtest/src/lib.rs

@@ -1,10 +1,17 @@
-//! `aura-backtest` — the backtest-execution node layer (C28): simulated execution
+//! `aura-backtest` — the backtest layer (C28): simulated execution without
-//! without money (the `SimBroker` pip yardstick, position management), measured in
+//! money (the `SimBroker` pip yardstick, position management), measured in R,
-//! R. Depends only on `aura-core`.
+//! plus the backtest metric reductions over the recorded streams
+//! (`metrics`, moved from `aura-analysis` by #291). Depends only on
+//! `aura-core` (+ serde for the metric types' C18 wire shapes).
 
+mod metrics;
 mod position_management;
 mod sim_broker;
 
+pub use metrics::{
+    derive_position_events, r_metrics_from_rs, summarize_r, PositionAction,
+    PositionEvent, RMetrics, RunMetrics,
+};
 pub use position_management::{
     ExitReason, FIELD_NAMES as PM_FIELD_NAMES, PositionManagement,
     RECORD_KINDS as PM_RECORD_KINDS, WIDTH as PM_WIDTH,

crates/aura-campaign/Cargo.toml

@@ -28,3 +28,9 @@ serde_json = { workspace = true }
 # work-stealing pool the engine's run_indexed already uses — parallelism across
 # sims, never within one. Direct versioned dep, mirroring aura-engine.
 rayon = "1"
+
+[dev-dependencies]
+# aura-backtest supplies RunMetrics/summarize_r for the metric-vocabulary drift
+# guard's direct-source import (tests/metric_vocabulary_e2e.rs). Production
+# code reaches these types via the aura-engine re-export instead.
+aura-backtest = { path = "../aura-backtest" }

crates/aura-campaign/tests/metric_vocabulary_e2e.rs

@@ -1,15 +1,17 @@
 //! Cross-crate guard for #190: pins `aura_research::metric_vocabulary()` (the
 //! hand-written 17-name declared metric roster) against the ACTUAL scalar
-//! fields the three metric-bearing `aura-analysis` types serialize — not a
+//! fields the three metric-bearing types serialize — `RunMetrics`/`RMetrics`
-//! second hand-list that could independently drift. `aura-campaign` is the
+//! from `aura-backtest` (via `summarize_r`), `FamilySelection` from
-//! one crate that already depends on both `aura-analysis` (the types) and
+//! `aura-analysis` — not a second hand-list that could independently drift.
-//! `aura-research` (the vocabulary), so it is the only place this pin can be
+//! `aura-campaign` is the one crate that already depends on the type sources
-//! written today (`aura-research` deliberately has no `aura-analysis` dep —
+//! and `aura-research` (the vocabulary), so this pin lives here
+//! (`aura-research` deliberately has no dep on either type crate —
 //! `metric_vocabulary`'s own doc comment names this as an accepted residual).
 
 use std::collections::BTreeSet;
 
-use aura_analysis::{summarize_r, FamilySelection, RunMetrics, SelectionMode};
+use aura_analysis::{FamilySelection, SelectionMode};
+use aura_backtest::{summarize_r, RunMetrics};
 
 /// The names of every field of a serialized sample whose JSON value is a
 /// `Number` — i.e. a scalar metric readout, not a string/enum tag, a nested

crates/aura-engine/Cargo.toml

@@ -7,11 +7,16 @@ publish.workspace = true
 
 [dependencies]
 aura-core = { path = "../aura-core" }
-# aura-analysis holds the pure trading-domain reductions (R-metrics, the
+# aura-analysis holds the domain-free post-run statistics and the
-# position-event table, the multiple-comparison hurdle math) lifted out of
+# selection-provenance types the engine's `RunManifest.selection` embeds
-# `report` (issue #136). The engine re-exports them via `report::` so callers
+# (#136, reduced to the domain-free half by #291). Re-exported via `report::`
-# resolve the moved types through aura-engine unchanged (C18 byte-identity).
+# so callers resolve the types through aura-engine unchanged (C18).
 aura-analysis = { path = "../aura-analysis" }
+# aura-backtest holds the backtest metric reductions re-exported through
+# `report::` (#291). TRANSIENT widening of the known C28 layer violation: the
+# phase-2 edge cut (#147) removes this production edge again on the same
+# branch.
+aura-backtest = { path = "../aura-backtest" }
 # serde is admitted under the amended C16 per-case dependency policy (INDEX.md):
 # it gives the run-report types a typed (de)serialization path for the run
 # registry (cycle 0029). serde's output is deterministic (C1-safe).
@@ -38,7 +43,6 @@ rayon = "1"
 aura-std = { path = "../aura-std" }
 aura-market = { path = "../aura-market" }
 aura-strategy = { path = "../aura-strategy" }
-aura-backtest = { path = "../aura-backtest" }
 aura-vocabulary = { path = "../aura-vocabulary" }
 # chrono / chrono-tz build the Berlin-local-wall-clock epoch-ns timestamps the
 # GER40 session-breakout E2E fixture (tests/ger40_breakout.rs) feeds the engine,

crates/aura-engine/src/report.rs

@@ -11,15 +11,17 @@
 use aura_core::{Scalar, ScalarKind, SeriesFold, Timestamp};
 use std::collections::HashMap;
 
-// The pure trading-domain reductions (R-metrics, the position-event table, the
+// The backtest reductions (R-metrics, the position-event table) live in
-// multiple-comparison hurdle math) live in `aura-analysis` (issue #136); they are
+// `aura-backtest::metrics`, the domain-free hurdle math + selection provenance
-// re-imported here so `report::`'s namespace — and therefore `aura-engine`'s
+// in `aura-analysis` (issues #136, #291); both are re-imported here so
-// `lib.rs` re-export and every `crate::report::X` reference — resolves unchanged
+// `report::`'s namespace — and therefore `aura-engine`'s `lib.rs` re-export and
-// (C18 byte-identity). `summarize` (below) bridges trace columns into these types
+// every `crate::report::X` reference — resolves unchanged (C18 byte-identity).
-// at the engine boundary, so it stays here.
+// `summarize` (below) bridges trace columns into these types at the engine
-pub use aura_analysis::{
+// boundary, so it stays here.
-    derive_position_events, expected_max_of_normals, inv_norm_cdf, r_metrics_from_rs, summarize_r,
+pub use aura_analysis::{expected_max_of_normals, inv_norm_cdf, FamilySelection, SelectionMode};
-    FamilySelection, PositionAction, PositionEvent, RMetrics, RunMetrics, SelectionMode,
+pub use aura_backtest::{
+    derive_position_events, r_metrics_from_rs, summarize_r, PositionAction,
+    PositionEvent, RMetrics, RunMetrics,
 };
 
 /// The reproducible run descriptor (C18). **Caller-supplied**: the engine

docs/design/INDEX.md

@@ -2667,14 +2667,16 @@ shell", #286).** This contract states the *target*. At HEAD the crates cut by
 mechanical role (vocabulary / reductions / documents / orchestration / CLI), not
 cleanly by layer, so the layering is realized only partially:
 - The dependency *direction* already nearly obeys the rule. The one hard
-  production violation is `aura-engine → aura-analysis`: `report.rs:20`
+  production violation is the engine's re-export of the backtest metrics —
-  re-exports the R-metrics, the position-event table, the hurdle math, and the
+  since the #291 split, `aura-engine → aura-backtest`: `report.rs` re-exports
-  selection-provenance types (`RMetrics`/`RunMetrics`/`summarize_r`/
+  the R-metrics and the position-event table (`RMetrics`/`RunMetrics`/
-  `r_metrics_from_rs`, `PositionEvent`/`PositionAction`/`derive_position_events`,
+  `summarize_r`/`r_metrics_from_rs`, `PositionEvent`/`PositionAction`/
-  `inv_norm_cdf`/`expected_max_of_normals`, `FamilySelection`/`SelectionMode`),
+  `derive_position_events`), and the generic-statistics kernel in `mc.rs`
-  and the generic-statistics kernel in `mc.rs` carries R/bias-typed fields
+  carries R/bias-typed fields (`McAggregate.bias_sign_flips`, `RBootstrap.e_r`)
-  (`McAggregate.bias_sign_flips`, `RBootstrap.e_r`) inside otherwise domain-free
+  inside otherwise domain-free structs. The `aura-engine → aura-analysis` edge
-  structs.
+  is no longer a violation: post-#291 that crate holds only domain-free
+  statistics + selection provenance (`FamilySelection` for
+  `RunManifest.selection`), foundation-grade under this contract.
 - **That violation is the exact surface of the deliberately-deferred #147.**
   Cutting it cleanly needs the metric genericity (`RunReport<M>` plus abstracting
   the registry deflation vocabulary) that #136 ratified *deferring* (user-ratified
@@ -2689,9 +2691,11 @@ cleanly by layer, so the layering is realized only partially:
   `aura-market` (`session`, `resample`), `aura-strategy` (`bias`/`stop_rule`/
   `sizer` + the cost nodes) and `aura-backtest` (`sim_broker`,
   `position_management`) carry the outer rungs, each depending only on `aura-core`;
-  the closed node roster moved to `aura-vocabulary`. The remaining in-crate
+  the closed node roster moved to `aura-vocabulary`. The `aura-analysis`
-  interweave is `aura-analysis`, which still holds backtest reductions and generic
+  interweave is resolved (phase 5, #291): the backtest reductions live in
-  hurdle math together (phase 5). No crate exists yet for *measurement* (its run
+  `aura-backtest::metrics` beside their `position_management` producer, and
+  `aura-analysis` is reduced to domain-free statistics + selection provenance
+  (`[dependencies]` = serde only). No crate exists yet for *measurement* (its run
   verb is the additive shape dispatch, #286) or *execution* (unbuilt — the C10/C13
   edge only). Under this model the `aura-registry → aura-research` edge is
   column-internal and legal.
@@ -2703,7 +2707,9 @@ cleanly by layer, so the layering is realized only partially:
   retention); (4) split the `aura-std` roster along engine / market / strategy /
   backtest — **done** (#288: four `aura-core`-only node crates, the closed roster
   moved to `aura-vocabulary`, the ladder direction enforced by a structural test);
-  (5) split `aura-analysis` into generic statistics and backtest metrics; (6)
+  (5) split `aura-analysis` into generic statistics and backtest metrics —
+  **done** (#291: metrics moved to `aura-backtest::metrics`, `aura-analysis`
+  reduced to the domain-free half, engine re-export surface name-unchanged); (6)
   generify the column's metric interface (demand-driven — this is #147). Crate
   names now realized (`aura-market`/`aura-strategy`/`aura-backtest`/
   `aura-vocabulary`); full evidence on #288, #286 and the milestone.