js-rigor: check() no longer strips reliability; TTU reliability pins

Bug 34: ArbiterChecks.check destructured { reliability, ...rest } out of
every normal (and binary) check result since the initial commit — the
engine computes reliability faithfully (TTU tupleset.reli * computed.reli,
direct relation reliability) and explain() preserved it, but the public
check() API silently dropped it. explain() kept it, so exposing it in
check() is the intended contract. The destructuring is removed; direct
and TTU checks now return reliability (0.6 / 0.72 in the pins).

Campaign pins added: TTU multi-path fusion (max over intermediates of
min(legs)) with reliability propagation through both persistent and
partial contexts, the maxIntermediates circuit breaker through partial,
and snapshot-restored arbiters evaluating TTU.

src/core/arbiter/ArbiterChecks.js

@@ -71,8 +71,7 @@ export class ArbiterChecks {
     }
     
     if (options.explain) return result;
-    const { reliability, ...rest } = result;
-    return rest;
+    return result;
   }
 
   explain(userKey, relation, objectKey, options = {}) {