js-rigor: possibilistic validity layer (Cella FVN labels, conflict mass, validification)

Adds an epistemic validity layer in the spirit of the zig-contour fusion
spec: every check result now carries a validity block {label, operator,
regime, sources, conflictMass, validifiedPossibility, nonMaxitive}.

- Relations accept a validity label (default heuristic = unlabeled input).
- Labels propagate through fusion: identity/max preserve the weakest
  source label (max is already valid under arbitrary dependence); min
  (conjunctive: intersection, chain, TTU, multi_hop, parent) is
  approximate at best, surfaces the conflict mass (1 - possibility) that
  was previously dropped, and exposes the arbitrary-regime validification
  min(1, K*gamma); product-style operators (exclusion, defeasible) and
  interior OWA averaging are always heuristic, with nonMaxitive flagged.
- Reliability and validity are now explicitly distinct: reliability stays
  the scalar confidence adaptation; validity tracks the epistemic label.
- The hottest paths attach a shared frozen default block instead of
  allocating (perf A/B shows no regression: ~300k ops/s direct both ways).
- Pre-existing fixes surfaced while wiring: the array-form logical config
  dropped top-level aggregator/owaWeights (average union compiled as max),
  and _createStandardResult dropped unknown fields (validity never
  survived rule results).

New campaign validity-parity.test.js pins the label taxonomy, conflict
mass, validification, weakest-propagation, and the reliability/validity
separation. Suites: rigor 203/0, full 803/741/0.

tests/rigor/binary-mode-parity.test.js

@@ -296,7 +296,8 @@ describe('Binary (threshold) mode parity (rigor)', () => {
 
     const inv = report.crucibleVerdict?.invariants?.find(i => i.name === 'binary-normal-agreement');
     assert.ok(inv, 'invariant missing');
-    assert.equal(inv.passed, true, `binary parity violated in ${inv.failureCount} cases`);
+    assert.equal(inv.passed, true, `binary parity violated in ${inv.failureCount} cases: ` +
+      JSON.stringify((report.failures || []).slice(0, 2).map(f => ({ name: f.name, msg: f.message, seq: (f.sequence || []).map(s => s.args) }))));
   });
 
   it('MUTATION FRESHNESS: binary and normal agree after every mutation with caching enabled', async () => {