build: add Vue and Pinia to the browser build and unit tests

build/vite.js

@@ -1,6 +1,7 @@
 import { fileURLToPath } from 'node:url';
 import { applicationHtmlPlugin } from './application-html.js';
 import cesium from 'vite-plugin-cesium';
+import vue from '@vitejs/plugin-vue';
 import { DEFAULT_ALLOWED_HOSTS, hostCheckPlugin } from './allowedHosts.js';
 import { embedFramingPlugin } from './embed-framing.js';
 import { panelBuildPlugin } from './panel.js';
@@ -156,6 +157,8 @@ export function createBrowserViteConfig({
       hostCheckPlugin(),
       cesium(),
       applicationHtmlPlugin(),
+      // Application views are Vue single-file components.
+      vue(),
       ...plugins,
       embedFramingPlugin(),
       panelBuildPlugin(),