fix(storage): deepen hyperbee secondary-index and hyperdrive snapshots

- Fix missing totalPrimaries() on bee-secondary-index (runtime bug in getStats)
- Add indexPutMany, lookupFirst, and tests for secondary index
- drive-version-snapshot: findByLabel, latestSnapshot, deleteSnapshot, merge gossip

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

storage-hyperdrive/hyper-p2p-drive-version-snapshot/index.js

@@ -58,10 +58,39 @@ class HyperP2PDriveVersionSnapshot extends EventEmitter {
     return this._snapshots.get(id) || null
   }
 
+  findByLabel (label) {
+    assertNonEmpty(label, 'label')
+    return this.listSnapshots().filter((s) => s.label === label)
+  }
+
+  latestSnapshot (label = null) {
+    const list = label ? this.findByLabel(label) : this.listSnapshots()
+    return list.length ? list[0] : null
+  }
+
+  deleteSnapshot (id) {
+    const ok = this._snapshots.delete(id)
+    if (ok) {
+      sendGossip(this, { type: 'snapshot-delete', id })
+      this._stats.gossipOut++
+      this.emit('delete', { id })
+    }
+    return ok
+  }
+
+  snapshotCount () {
+    return this._snapshots.size
+  }
+
   _onGossip (d) {
+    if (d?.type === 'snapshot-delete') {
+      this._snapshots.delete(d.id)
+      return
+    }
     if (!d || d.type !== 'snapshot' || !d.snap) return
     this._stats.gossipIn++
-    this._snapshots.set(d.snap.id, d.snap)
+    const prev = this._snapshots.get(d.snap.id)
+    if (!prev || d.snap.at >= prev.at) this._snapshots.set(d.snap.id, d.snap)
   }
 
   getStats () {