fix showLoading dark theme & add doubleTap to connect

flutter/lib/common.dart

@@ -200,7 +200,6 @@ class OverlayDialogManager {
       VoidCallback? onCancel}) {
     show((setState, close) => CustomAlertDialog(
         content: Container(
-            color: MyTheme.white,
             constraints: BoxConstraints(maxWidth: 240),
             child: Column(
                 mainAxisSize: MainAxisSize.min,

flutter/lib/desktop/widgets/peercard_widget.dart

@@ -53,7 +53,9 @@ class _PeerCardState extends State<_PeerCard>
                 border: Border.all(color: Colors.transparent, width: 1.0),
                 borderRadius: BorderRadius.circular(20));
           },
-          child: _buildPeerTile(context, peer, deco),
+          child: GestureDetector(
+              onDoubleTap: () => _connect(peer.id),
+              child: _buildPeerTile(context, peer, deco)),
         ));
   }