feat(client): polished toolbar, live online count via SSE

- Redesign in-game client toolbar with refined glass styling and buttons
- Live online count + emulator status streamed over SSE multicast
- Who's-online tooltip throttled to reduce repeated requests
- Fix show button so it always returns the hidden toolbar
- Use theme CSS variables instead of hardcoded colors
- Add toolbar translations across all 25 locales

src/messages/es.json

@@ -3263,5 +3263,18 @@
 			"button": "Verify email",
 			"fallback": "If the button doesn't work, paste this link into your browser:"
 		}
+	},
+	"toolbar": {
+		"home": "Inicio",
+		"reload": "Recargar",
+		"fullscreen": "Pantalla completa",
+		"logout": "Cerrar sesión",
+		"onlineUsers": "Usuarios en línea",
+		"emulatorOnline": "Emulador en línea",
+		"emulatorOffline": "Emulador fuera de línea",
+		"dragToMove": "Arrastra para mover",
+		"hide": "Ocultar barra",
+		"fullscreenExit": "Salir de pantalla completa",
+		"show": "Mostrar barra"
 	}
 }