Tray state icon and window picture; firewall rules without the comment match; macOS app bundle

The tray icon is dark red with no connection (or a lost exit node), blue when
connected and green while an exit node is in use; the windows get the logo and
an app id that matches the desktop entry, and the exit icon moves to the
bottom left of the tile. Exit-node and broadcast firewall rules fall back to
being recognised by their shape on kernels that have no `comment` match, as
small router builds do. The macOS archive carries Tsunagi.app for the Homebrew
cask, and the daemon plist opens the control socket to the admin group.

Co-Authored-By: Claude <noreply@anthropic.com>

dist/linux/tsunagi-tray.desktop

@@ -9,3 +9,4 @@ Terminal=false
 Categories=Network;Utility;
 Keywords=mesh;vpn;overlay;network;
 StartupNotify=false
+StartupWMClass=tsunagi-tray