Fix WG watcher missing initial handshake (#5213)

Start the WireGuard watcher before configuring the WG endpoint to ensure it captures the initial handshake timestamp.

Previously, the watcher was started after endpoint configuration, causing it to miss the handshake that occurred during setup.

client/internal/peer/conn.go

@@ -390,6 +390,8 @@ func (conn *Conn) onICEConnectionIsReady(priority conntype.ConnPriority, iceConn
 	}
 
 	conn.Log.Infof("configure WireGuard endpoint to: %s", ep.String())
+	conn.enableWgWatcherIfNeeded()
+
 	presharedKey := conn.presharedKey(iceConnInfo.RosenpassPubKey)
 	if err = conn.endpointUpdater.ConfigureWGEndpoint(ep, presharedKey); err != nil {
 		conn.handleConfigurationFailure(err, wgProxy)
@@ -402,8 +404,6 @@ func (conn *Conn) onICEConnectionIsReady(priority conntype.ConnPriority, iceConn
 		conn.wgProxyRelay.RedirectAs(ep)
 	}
 
-	conn.enableWgWatcherIfNeeded()
-
 	conn.currentConnPriority = priority
 	conn.statusICE.SetConnected()
 	conn.updateIceState(iceConnInfo)
@@ -501,6 +501,9 @@ func (conn *Conn) onRelayConnectionIsReady(rci RelayConnInfo) {
 
 	wgProxy.Work()
 	presharedKey := conn.presharedKey(rci.rosenpassPubKey)
+
+	conn.enableWgWatcherIfNeeded()
+
 	if err := conn.endpointUpdater.ConfigureWGEndpoint(wgProxy.EndpointAddr(), presharedKey); err != nil {
 		if err := wgProxy.CloseConn(); err != nil {
 			conn.Log.Warnf("Failed to close relay connection: %v", err)
@@ -509,8 +512,6 @@ func (conn *Conn) onRelayConnectionIsReady(rci RelayConnInfo) {
 		return
 	}
 
-	conn.enableWgWatcherIfNeeded()
-
 	wgConfigWorkaround()
 	conn.rosenpassRemoteKey = rci.rosenpassPubKey
 	conn.currentConnPriority = conntype.Relay