Add <v-app-bar/> extension info to router.

The idea is for the <dougal-navigation/> component to dynamically
load the extension, if any, defined in the route's meta attribute.

lib/www/client/source/src/router/index.js

@@ -16,7 +16,7 @@ import Log from '../views/Log.vue'
 import QC from '../views/QC.vue'
 import Graphs from '../views/Graphs.vue'
 import Map from '../views/Map.vue'
-
+import DougalAppBarExtensionProject from '../components/app-bar-extension-project'
 
 Vue.use(VueRouter)
 
@@ -100,7 +100,10 @@ Vue.use(VueRouter)
           text: (ctx) => ctx.$store.state.project.projectName || "…",
           href: (ctx) => `/projects/${ctx.$store.state.project.projectId || ctx.$route.params.project || ""}/`
         }
-      ]
+      ],
+      appBarExtension: {
+        component: DougalAppBarExtensionProject
+      }
     },
     children: [
       {