Centralize heartbeat logic in PeerManager

- Remove redundant HeartbeatManager::heartbeat() wrapper function
- Consolidate all heartbeat logic directly in PeerManager::heartbeat()
- Simplify HeartbeatManager to only handle timing (poll_tick)
- Clean up unused imports in heartbeat.rs
- Improve code organization with clear separation of concerns:
  - HeartbeatManager: Timer management only
  - PeerManager: All heartbeat logic and orchestration
  - PeerDiscovery: Peer discovery/connection logic

This eliminates an unnecessary layer of indirection and centralizes
heartbeat functionality for better maintainability.

Author: diegomrsantos

anchor/network/src/peer_manager/heartbeat.rs

@@ -1,13 +1,6 @@
-use std::{collections::HashSet, time::Duration};
+use std::time::Duration;
 
-use discv5::libp2p_identity::PeerId;
-use peer_store::memory_store::MemoryStore;
-use subnet_service::SubnetId;
 use tokio::time::{MissedTickBehavior, interval};
-use tracing::info;
-
-use super::{connection::ConnectionManager, discovery::PeerDiscovery, types::ConnectActions};
-use crate::Enr;
 
 /// Interval between heartbeat events in seconds
 const HEARTBEAT_INTERVAL: u64 = 30;
@@ -32,25 +25,4 @@ impl HeartbeatManager {
     ) -> std::task::Poll<tokio::time::Instant> {
         self.heartbeat.poll_tick(cx)
     }
-
-    /// Log network status and check for needed peer actions
-    pub fn heartbeat(
-        needed_subnets: &HashSet<SubnetId>,
-        peer_store: &MemoryStore<Enr>,
-        connection_manager: &ConnectionManager,
-        blocked_peers: &HashSet<PeerId>,
-    ) -> Option<ConnectActions> {
-        info!(
-            subnets = needed_subnets.len(),
-            peers = connection_manager.connected.len(),
-            "Network status"
-        );
-
-        PeerDiscovery::check_subnet_peers(
-            needed_subnets,
-            peer_store,
-            connection_manager,
-            blocked_peers,
-        )
-    }
 }

anchor/network/src/peer_manager/mod.rs

@@ -92,7 +92,8 @@ impl PeerManager {
         // Check and unblock peers that have been blocked long enough
         self.blocking_manager.check_and_unblock_expired_peers();
 
-        HeartbeatManager::heartbeat(
+        // Check if any subnets need more peers and return dial/discovery actions
+        PeerDiscovery::check_subnet_peers(
             &self.needed_subnets,
             self.peer_store.store(),
             &self.connection_manager,