Update configs and complete Svelte 5 upgrade

Co-authored-by: caged <25+caged@users.noreply.github.com>

Author: Copilot

package-lock.json

@@ -16,6 +16,7 @@
   },
   "devDependencies": {
     "@sveltejs/vite-plugin-svelte": "^5.0.4",
+    "@web/dev-server-esbuild": "^1.0.4",
     "@web/test-runner": "^0.12.17",
     "autoprefixer": "^10.4.4",
     "chai": "^4.2.0",

package.json

@@ -1,10 +1,10 @@
 // web-test-runner.config.js
+import { esbuildPlugin } from '@web/dev-server-esbuild';
 
-// NOTE: For now, NODE_ENV needs to be set to "test" for Snowpack
-// to build test files properly. We hope to remove this limitation
-// in a future release.
-process.env.NODE_ENV = 'test'
+export default {
+  nodeResolve: {
+    exportConditions: ['default', 'module', 'import']
+  },
+  plugins: [esbuildPlugin({ ts: false, js: true, target: 'auto' })],
+};
 
-module.exports = {
-  plugins: [require('@snowpack/web-test-runner-plugin')()],
-}