fix: route connect responses through upstream_addr

When accepting a connect request, route the response and observed address
messages through the upstream peer (where the request came from) rather than
trying to send directly to the joiner. The accepting peer may not have a
direct connection to the joiner in relay scenarios.

This mirrors how response forwarding already works at line 989-994.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: sanity

crates/core/src/operations/connect.rs

@@ -830,11 +830,9 @@ impl Operation for ConnectOp {
                         };
                         // Route through upstream (where the request came from) since we may
                         // not have a direct connection to the target
-                        if let Some(upstream) = source_addr {
-                            network_bridge
-                                .send(upstream, NetMessage::V1(NetMessageV1::Connect(msg)))
-                                .await?;
-                        }
+                        network_bridge
+                            .send(upstream_addr, NetMessage::V1(NetMessageV1::Connect(msg)))
+                            .await?;
                     }
 
                     if let Some(peer) = actions.expect_connection_from {
@@ -876,14 +874,12 @@ impl Operation for ConnectOp {
                         };
                         // Route the response through upstream (where the request came from)
                         // since we may not have a direct connection to the joiner
-                        if let Some(upstream) = source_addr {
-                            network_bridge
-                                .send(
-                                    upstream,
-                                    NetMessage::V1(NetMessageV1::Connect(response_msg)),
-                                )
-                                .await?;
-                        }
+                        network_bridge
+                            .send(
+                                upstream_addr,
+                                NetMessage::V1(NetMessageV1::Connect(response_msg)),
+                            )
+                            .await?;
                         return Ok(store_operation_state(&mut self));
                     }