Deconflict Webpack's dev-server websocket.

It uses /ws which is the same path Dougal uses.

Changing Dougal's path to something more imaginative requires
reconfiguring Nginx though.

lib/www/client/source/vue.config.js

@@ -5,6 +5,18 @@ module.exports = {
   ],
   devServer: {
     host: "0.0.0.0",
+    webSocketServer: {
+      // Not found in the Webpack docs. Reference:
+      // https://github.com/webpack/webpack-dev-server/blob/540c43852ea33f9cb18820e1cef05d5ddb86cc3e/lib/servers/WebsocketServer.js#L21
+      options: {
+        // Not found in the ws docs. Reference:
+        // https://github.com/websockets/ws/blob/d8dd4852b81982fc0a6d633673968dff90985000/lib/websocket-server.js#L68
+        path: "/webpack-dev-server"
+      }
+    },
+    client: {
+      webSocketURL: "auto://0.0.0.0:0/webpack-dev-server"
+    },
     proxy: {
       "^/api(/|$)": {
         target: "http://127.0.0.1:3000",