test(frontend): add unit testing with Vitest and CI integration (#35)

* Initialized Vitest and added first test for frontend

* Updated GitHub CI to run frontend unit tests

* Added test for useEnhancedToast composable

* Updated CI Node version to 24

Author: ivanskv2000

.github/workflows/frontend.yml

@@ -24,7 +24,7 @@ jobs:
       - name: Set up Node.js
         uses: actions/setup-node@v4
         with:
-          node-version: '21'
+          node-version: '24'
           cache: 'npm'
           cache-dependency-path: frontend/package-lock.json
 
@@ -36,3 +36,28 @@ jobs:
 
       - name: Run ESLint
         run: npm run lint
+
+  test:
+    name: Run Unit Tests
+    runs-on: ubuntu-latest
+
+    defaults:
+      run:
+        working-directory: ./frontend
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '24'
+          cache: 'npm'
+          cache-dependency-path: frontend/package-lock.json
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Run Vitest
+        run: npm run test:unit