refactor: remove unused location field from InboundConnection event

As suggested in PR review, the location field was marked with #[allow(dead_code)]
and not being used. The connection is only added to ConnectionManager after
StartJoinReq is accepted, not when InboundConnection event is processed.

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

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

Author: sanity

crates/core/src/node/network_bridge/handshake.rs

@@ -62,8 +62,6 @@ pub(super) enum Event {
         id: Transaction,
         conn: PeerConnection,
         joiner: PeerId,
-        #[allow(dead_code)]
-        location: Location,
         op: Option<Box<ConnectOp>>,
         forward_info: Option<Box<ForwardInfo>>,
     },
@@ -463,7 +461,6 @@ impl HandshakeHandler {
                                     id,
                                     conn,
                                     joiner,
-                                    location,
                                     op: ok.map(|ok_value| Box::new(ConnectOp::new(id, Some(ok_value), None, None))),
                                     forward_info: forward_info.map(Box::new),
                                 })

crates/core/src/node/network_bridge/p2p_protoc.rs

@@ -782,7 +782,6 @@ impl P2pConnManager {
                 id,
                 conn,
                 joiner,
-                location: _, // Not used - connection only added after StartJoinReq accepted
                 op,
                 forward_info,
             } => {