feat: the IC becomes the second metric vocabulary; rosters single-sourced

The A1 cut of #147 item 2, part 2 of 2 (the consumers), completing what
part 1 (the MetricVocabulary substrate) set up:

- aura-campaign's RANKABLE_METRICS hand-copy becomes a re-export of the
  backtest vocabulary's roster; the #190 guard test extends to pin the
  roster nesting (rankable == vocabulary roster, rankable within
  per-member, per-member within the research vocabulary) and the legacy
  exposure_sign_flips alias, so any drift fails a test loudly. The
  research and per-member rosters themselves stay hand-copies by ratified
  isolation (#190 accepted residual) — now oracle-pinned instead of trusted.
- aura-cli gains IcMetrics + IcKey implementing MetricVocabulary: the
  second PRODUCTION implementor. The standalone `aura measure ic`
  reduction now computes its permutation p via the shared null_draw +
  one_sided_p_laplace building blocks (independent draws instead of
  chained shuffles — statistically equivalent, deterministic per seed;
  emitted p values may differ in the last digits from #290's).
- Acceptance proven at the registry boundary: an engineered
  SweepFamily<IcMetrics> deflates through optimize_deflated to a LOW
  overfit probability and a noise family to a HIGH one (the permutation
  null, dispatched by the vocabulary — the deflation machinery is no
  longer baked-in R-only); same seed reproduces the identical
  FamilySelection; cross-vocabulary names are refused with the family's
  own roster in the prose (the C10 guard). A new cli_run E2E exercises
  the legacy alias through the real `aura runs family … rank` boundary.

Deviation from the plan, forced by the compiler: IcMetrics additionally
derives Debug (unwrap_err on the deflation Result needs it; mirrors
RunMetrics).

Verification: full workspace suite green (no FAILED, no compile errors),
clippy -D warnings clean, C18 goldens (cli_run, measure_ic, c28_layering)
green unchanged. A2 — measurement runs as sweep-family citizens — stays
deliberately deferred until a concrete campaign demand exists.

closes #147

crates/aura-campaign/src/lib.rs

@@ -144,14 +144,10 @@ pub const PER_MEMBER_METRICS: &[&str] = &[
     "sqn", "net_expectancy_r",
 ];
 
-/// The registry's rankable roster (`resolve_metric`'s name set) — the metrics
-/// a sweep/walk_forward stage may select on. Hand-copied (#190); drift fails
-/// safe (a name the registry would refuse is refused here first, before any
-/// member runs).
-pub const RANKABLE_METRICS: &[&str] = &[
-    "total_pips", "max_drawdown", "bias_sign_flips",
-    "sqn", "sqn_normalized", "expectancy_r", "net_expectancy_r",
-];
+/// The rankable subset a stage's `rank_by`/`select` may name — re-exported
+/// from the backtest vocabulary (single source, #147): this roster and the
+/// registry's refusal prose can no longer drift.
+pub use aura_backtest::RANKABLE_METRICS;
 
 /// Deflation resample count — re-exported from `aura-registry`'s shared
 /// definition (single-sourced, #199).

crates/aura-campaign/tests/metric_vocabulary_e2e.rs

@@ -107,3 +107,31 @@ fn metric_vocabulary_covers_all_shipped_scalar_metrics() {
          top-level enumeration)"
     );
 }
+
+/// #147: the rankable roster is single-sourced from the vocabulary impl, the
+/// rosters nest (rankable ⊆ per-member ⊆ research vocabulary), and the legacy
+/// CLI alias keeps resolving. Any drift fails here, loudly.
+#[test]
+fn rankable_roster_is_single_sourced_and_nested() {
+    use aura_engine::MetricVocabulary;
+
+    assert_eq!(
+        aura_campaign::RANKABLE_METRICS,
+        <RunMetrics as MetricVocabulary>::known(),
+        "campaign roster must BE the vocabulary's roster"
+    );
+    for name in aura_campaign::RANKABLE_METRICS {
+        assert!(
+            aura_campaign::PER_MEMBER_METRICS.contains(name),
+            "rankable metric '{name}' missing from PER_MEMBER_METRICS"
+        );
+    }
+    for name in aura_campaign::PER_MEMBER_METRICS {
+        assert!(
+            aura_research::metric_vocabulary().contains(name),
+            "per-member metric '{name}' missing from the research vocabulary"
+        );
+    }
+    // the pre-rename CLI alias must keep resolving (back-compat).
+    assert!(<RunMetrics as MetricVocabulary>::resolve("exposure_sign_flips").is_some());
+}