Add hasKey() and getKey() helpers across keyed modules (tenth pass).

Domain-aware lookup aliases on modules that already expose listKeys/keyCount, including async indexes and probabilistic bloom sets.

Co-authored-by: Cursor <[email protected]>

network-stack/hyper-p2p-overlay-topology/index.js

@@ -116,6 +116,14 @@ class HyperP2POverlayTopology extends EventEmitter {
     return this.size()
   }
 
+  hasKey (key) {
+    return this.hasNeighbor(key)
+  }
+
+  getKey (key) {
+    return this._neighbors.get(String(key)) ?? null
+  }
+
   getStats () {
     return { ...this._stats, degree: this._neighbors.size, protocol: PROTOCOL }
   }