Add reproducible browser and accessibility gates

web/vite.config.ts

@@ -1,15 +1,21 @@
 import { svelte } from '@sveltejs/vite-plugin-svelte';
-import { defineConfig, loadEnv } from 'vite';
+import { loadEnv } from 'vite';
+import { defineConfig } from 'vitest/config';
 
 export default defineConfig(({ mode }) => {
   const backend =
     loadEnv(mode, '.', '').NUTHATCH_DEV_BACKEND ?? 'http://127.0.0.1:8080';
   return {
     plugins: [svelte()],
+    resolve: mode === 'test' ? { conditions: ['browser'] } : undefined,
     build: {
       manifest: true,
       sourcemap: false
     },
+    test: {
+      environment: 'jsdom',
+      include: ['test/components/**/*.test.ts']
+    },
     server: {
       proxy: {
         '/api': backend,