feat(api): add peer management to admin RPC

[317787106]

What does this PR do?

This PR adds runtime peer management to the Admin JSON-RPC API over both HTTP and IPC. It introduces admin_addPeer, admin_removePeer, admin_disconnectPeer, admin_listActivePeers, admin_blockIp, admin_unblockIp, and admin_listBlockedIps.

Active nodes can be added or removed without restarting the node, while an exact peer connection can be disconnected independently. Manually blocked IPs are persisted in CommonStore under blocked-ips, loaded before libp2p starts, applied to TCP connections, and exposed through the Admin API. Invalid persisted data is deleted on a best-effort basis and does not prevent network startup.

The active-peer response reuses the immutable statistics used by PeerConnection.log(), including connection, latency, and synchronization state. Peer and blocked-IP mutations share one structured PeerOperationResult response.

Why are these changes required?

Operators need a way to react immediately after identifying a malicious peer: disconnecting or blocking it cuts the attack path, while adding a trusted endpoint restores useful connectivity without restarting the node. This helps preserve synchronization, block production, and message propagation during Sybil or isolation attacks.

Behavior notes

• admin_addPeer adds an active node but does not add it to trustNodes.
• When node.dynamicConfig.enable is enabled, add/remove active-node operations return a structured failure directing operators to update node.active instead.
• Adding an endpoint whose IP is manually blocked is rejected.
• Blocking an IP persists the new snapshot before applying it to libp2p and disconnecting matching TCP connections.
• The first phase does not filter UDP discovery traffic from Kademlia or DNS discovery.
• No new peer-management configuration switch is introduced; existing Admin HTTP/IPC controls remain authoritative.

Testing

• Added unit coverage for startup loading, corrupt-data recovery, persistence ordering, idempotency, concurrent block updates, active-node operations, blocked-IP conflicts, dynamic-config behavior, and active-peer statistics.
• Added HTTP and IPC dispatch/error-code coverage for the new methods.
• Added lifecycle and effective-connection compatibility tests.
• checkstyleMain, checkstyleTest, and the related framework test suites pass.

Follow-up

Use the released libp2p version after the dependent PR is merged; UDP discovery filtering can be considered in a later phase.

Extra details

Depends on libp2p PR #6. No protobuf, P2P wire-message, consensus, or chain-data format changes are introduced.