fix(kad-dht): prefer connected peers to reduce unnecessary dials

[paschal533]

Summary

Reduces unnecessary new dials in the Amino DHT by preferring already-connected peers at three levels:

Tier 1 Query manager: connected-peers-first path distribution (query/manager.ts)

Before distributing the K closest routing-table peers into D disjoint query paths, sort them so already-connected peers come first. With a round-robin bucket assignment, each path gets a connected peer as its starting point, reducing the cold-dial penalty at the beginning of every DHT query.

Tier 2 Content routing: connected-peers-first ADD_PROVIDER fan-out (content-routing/index.ts)

After collecting the K closest FINAL_PEER events during provide(), sort them by connection status before enqueuing the parallel ADD_PROVIDER sends. The first ALPHA queue slots go to already-connected peers, so provider records reach the network with fewer new dials.

Tier 3 Reprovider: Kademlia key order sweep (reprovider.ts)

Port go-libp2p's SweepingProvider optimisation. processRecords now collects all CIDs that need reproviding, computes their Kademlia keys, sorts them lexicographically, and queues reprovides in that order. XOR-adjacent CIDs share the same K closest peers, so connections opened for one CID are reused for the next, reducing the total number of new dials across a reprovide run.

Test plan

• query.spec.ts verifies each disjoint path gets at least one connected starting peer when connected peers are available
• content-routing.spec.ts verifies connectionManager.getConnections is called during provide() for the connected-first sort
• reprovider.spec.ts inserts 5 CIDs in reverse Kademlia key order, then verifies contentRouting.provide is called in ascending Kademlia key order
• All 152 existing tests continue to pass
• Lint and TypeScript build clean