audit: cycle metric-vocabulary tidy — ledger records the retired #147 deferral

Cycle-close audit (architect: drift_found, design core clean). What holds,
architect-confirmed: C18 bit-identity for RunMetrics (prose derived
byte-identically, rng order preserved, registry suite unchanged); the C10
wall (monomorphic R-gates, r_based in the R vocabulary, cross-vocabulary
refusal tested both ways — no leak); C28 direction (trait in aura-analysis,
vocabulary supplied from the outer rungs, zero Cargo edge changes); C1
determinism pinned through the generic path.

Drift items, all resolved as fixes in this commit:
- design ledger: the C28 #147 disposition now records item 2 SHIPPED (the
  A1 cut) with A2 still deliberately deferred; the #136 one-implementor
  clause carries a supersession note (the IC is the second implementor).
- seven stale doc comments describing the pre-#147 or mid-cycle state
  (analysis trait + estimator docs, registry check_r_metric C9 claim,
  engine re-export note, campaign PER_MEMBER_METRICS roster note,
  member-seam guard comment, research vocabulary note) updated to the
  shipped state.
- R_BASED_METRICS is now oracle-pinned against RunMetricKey::r_based()
  in the vocabulary test (it feeds the NonRMetric refusal prose; a
  divergence would have misreported the R-gate silently).

Noted, not amended (history stays): commit 6744f67's body says 'three
syntax-only edits' where the test module actually took five.

No regression scripts are configured (the bench is report-only); the
architect review is the gate. Verification: extended vocabulary test,
campaign suites, analysis/research suites green; clippy --workspace
-D warnings clean.

refs #147

crates/aura-backtest/src/metrics.rs

@@ -1389,6 +1389,22 @@ mod tests {
         assert_eq!(<RunMetrics as MetricVocabulary>::known(), RANKABLE_METRICS);
         assert!(RunMetricKey::Sqn.r_based());
         assert!(!RunMetricKey::TotalPips.r_based());
+        // Oracle-pin R_BASED_METRICS against the classification itself: the
+        // const feeds the NonRMetric refusal prose, so a divergence would
+        // misreport the R-gate silently rather than fail a lookup.
+        let derived: Vec<&str> = RANKABLE_METRICS
+            .iter()
+            .copied()
+            .filter(|n| {
+                <RunMetrics as MetricVocabulary>::resolve(n)
+                    .expect("roster names resolve")
+                    .r_based()
+            })
+            .collect();
+        assert_eq!(
+            derived, R_BASED_METRICS,
+            "R_BASED_METRICS must be exactly the r_based slice of the roster"
+        );
     }
 
     /// Property: an R-based key on a member with no `r` block ranks worst for