fix(network): add immediate peer addition to gossipsub mesh and enable flood publishing

- Implemented a critical fix to add peers as explicit gossipsub peers immediately after connection, ensuring they are included in the mesh for all topics without delay.
- Enabled flood publishing for small networks to ensure messages are sent to all connected peers immediately, addressing issues in 2-node networks where mesh formation can be delayed.

Author: michaelgpt

app/src/actors_v2/network/network_actor.rs

@@ -329,6 +329,25 @@ impl NetworkActor {
                     endpoint.get_remote_address().to_string(),
                 );
                 self.metrics.record_connection_established();
+
+                // CRITICAL FIX FOR ISSUE #2: Add peer as explicit gossipsub peer immediately
+                // This ensures the peer is added to the gossipsub mesh for all topics
+                // without waiting for the heartbeat tick (which can take 1+ seconds)
+                if let Some(cmd_tx) = &self.swarm_cmd_tx {
+                    let cmd = SwarmCommand::AddExplicitPeer { peer_id };
+                    if let Err(e) = cmd_tx.try_send(cmd) {
+                        tracing::warn!(
+                            peer_id = %peer_id,
+                            error = ?e,
+                            "Failed to send AddExplicitPeer command after connection"
+                        );
+                    } else {
+                        tracing::debug!(
+                            peer_id = %peer_id,
+                            "Sent AddExplicitPeer command for immediate mesh formation"
+                        );
+                    }
+                }
             }
 
             SwarmEvent::ConnectionClosed { peer_id, cause, .. } => {

app/src/actors_v2/network/swarm_factory.rs

@@ -82,6 +82,11 @@ fn create_behaviour(
         // Relax gossip parameters for small networks
         .gossip_lazy(3) // Gossip to this many peers (default: 6)
         .gossip_factor(0.5) // Gossip factor (default: 0.25)
+        // CRITICAL FIX: Enable flood publishing for small networks
+        // This ensures messages are sent to all connected peers immediately,
+        // even if the mesh hasn't formed yet. Essential for 2-node networks
+        // where mesh formation can be delayed.
+        .flood_publish(true) // Flood messages to all connected peers (default: false)
         .message_id_fn(|msg: &gossipsub::Message| {
             // Use first 20 bytes of hash as message ID
             let mut hasher = DefaultHasher::new();