feat(media-streaming,pubsub): expand helper swarm and chunk scheduler APIs

- helper-swarm-coordinator: autoAssign, rebalance, resetUtilization
- chunk-scheduler-media: enqueueBatch, dropBelowPriority, clear
- qos-topic: queueDepths, clearQueues
- Update routing-advanced category README highlights

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

messaging-pubsub/hyper-p2p-qos-topic/index.js

@@ -75,6 +75,19 @@ class HyperP2PQosTopic extends EventEmitter {
 
   hasHandler (channel) { return this._handlers.has(channel) }
 
+  queueDepths () {
+    return this._queues.map((q, qos) => ({ qos, depth: q.length }))
+  }
+
+  clearQueues () {
+    let n = 0
+    for (const q of this._queues) {
+      n += q.length
+      q.length = 0
+    }
+    return n
+  }
+
   _onGossip (data) {
     if (!data || data.type !== 'qos-publish') return
     this._stats.gossipIn++