fix(pool): track channels by instance when remote addresses collide

[317787106]

What does this PR do?

• Track connection-pool entries by Channel instance when different TCP channels have the same remote InetSocketAddress.
• Keep active/passive peer counters aligned with the channel that is being connected or disconnected.
• Prevent same-address channels from being collapsed by Channel.equals() during pool lifecycle bookkeeping.

Why are these changes required?

Channel.equals() currently identifies a channel only by its remote socket address. If the remote host supports TCP source-port reuse and uses its listening port as the source port of an inbound connection, an inbound and an outbound channel can have the same remote address while remaining different TCP connections.

The pool could then skip counting the second channel, but later decrement the counter according to the direction of the channel being closed while removing the other channel from the tracked set. Repeated occurrences could leave active/passive tracking inconsistent and affect subsequent connection decisions.

The fix uses channel-instance identity for pool membership and removal. The TCP port-reuse capability is a prerequisite for the address collision; ordinary inbound and outbound connections normally use different remote ports.

This PR has been tested by:

• Added lifecycle tests for same-address inbound and outbound channels in both close orders.
• Tested duplicate close notifications, an unregistered channel, replacement notifications, and repeated connect/disconnect cycles.
• Verified that active/passive counters and tracked channel instances remain consistent.
• git diff --check passed.

Follow up

Keep the existing remote-address mapping in ChannelManager under review separately; this PR is limited to connection-pool bookkeeping.

Extra details

This change does not modify the wire protocol or require a protocol upgrade.

[3for]

[SHOULD, java-tron follow-up] Please use channel identity (==) in getPeerConnection() and identity-based removal throughout PeerManager, including check().

Distinct channels sharing a remote address currently resolve to the same PeerConnection, which can skip handshake initialization, misassociate messages, and remove another connection's record. Please add tests covering both removal orders and duplicate disconnect callbacks.

[317787106]

[SHOULD, java-tron follow-up] Please use channel identity (==) in getPeerConnection() and identity-based removal throughout PeerManager, including check().

Distinct channels sharing a remote address currently resolve to the same PeerConnection, which can skip handshake initialization, misassociate messages, and remove another connection's record. Please add tests covering both removal orders and duplicate disconnect callbacks.

I will fix it in java-tron's PR also. If issues, i will comment it here.

[3for]

LGTM.