fix: add missing test dependencies to devDependencies (#28)

vitest, @testing-library/react, @testing-library/user-event,
@testing-library/jest-dom, jsdom, react, react-dom, @mui/material,
and react-router-dom were all used directly but only available as
transitive dependencies through @kinvolk/headlamp-plugin. pnpm's
strict module resolution prevented them from being resolved.

Also adds process.env.NODE_ENV="test" to vitest config so React
loads its development build (required for act() support in tests).

Fixes #27

Co-authored-by: gandalf-the-greybeard[bot] <gandalf-the-greybeard[bot]@users.noreply.github.com>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

package.json

@@ -26,8 +26,21 @@
     "e2e": "playwright test",
     "e2e:headed": "playwright test --headed"
   },
+  "peerDependencies": {
+    "react": "^18.0.0",
+    "react-dom": "^18.0.0"
+  },
   "devDependencies": {
     "@kinvolk/headlamp-plugin": "^0.13.0",
-    "@playwright/test": "^1.58.2"
+    "@mui/material": "^5.15.14",
+    "@playwright/test": "^1.58.2",
+    "@testing-library/jest-dom": "^6.4.8",
+    "@testing-library/react": "^16.0.0",
+    "@testing-library/user-event": "^14.5.2",
+    "jsdom": "^24.0.0",
+    "react": "^18.3.1",
+    "react-dom": "^18.3.1",
+    "react-router-dom": "^5.3.0",
+    "vitest": "^3.0.5"
   }
 }

vitest.config.mts

@@ -1,6 +1,9 @@
 import { defineConfig } from 'vitest/config';
 
 export default defineConfig({
+  define: {
+    'process.env.NODE_ENV': '"test"',
+  },
   test: {
     globals: true,
     environment: 'jsdom',