js-rigor: partial-graph policy limits now enforce; binary-partial pins

- Arbiter constructor and setPartialGraphPolicy dropped maxNodes,
  maxRelations, and reservedRelations — the partial-graph context always
  saw the 1000/2000 defaults, silently disabling configured DoS guards.
  Both paths now carry the limits through; policy limits test pins
  constructor + setter enforcement and custom reservedRelations.

src/core/Arbiter.js

@@ -130,7 +130,13 @@ export class Arbiter {
         || 'deterministic',
       reducers: {
         ...(options?.partialGraphPolicy?.reducers || {})
-      }
+      },
+      // Size/reserved limits must survive construction: the partial-graph
+      // context reads them from the policy, and dropping them silently
+      // disabled configured DoS guards (defaults 1000/2000 applied).
+      maxNodes: options?.partialGraphPolicy?.maxNodes,
+      maxRelations: options?.partialGraphPolicy?.maxRelations,
+      reservedRelations: options?.partialGraphPolicy?.reservedRelations
     };
 
     this.snapshotEnabled = false;

src/core/arbiter/ArbiterConfig.js

@@ -62,7 +62,10 @@ export class ArbiterConfig {
 
     this.arbiter.partialGraphPolicy = {
       conflict_mode: conflictMode,
-      reducers
+      reducers,
+      maxNodes: next.maxNodes !== undefined ? next.maxNodes : current.maxNodes,
+      maxRelations: next.maxRelations !== undefined ? next.maxRelations : current.maxRelations,
+      reservedRelations: next.reservedRelations !== undefined ? next.reservedRelations : current.reservedRelations
     };
     return this.arbiter.partialGraphPolicy;
   }