Fix GitHub Action: Use working-directory instead of --prefix for npm ci

Author: CodeAurelius0

.github/workflows/deploy-pages.yml

@@ -25,12 +25,14 @@ jobs:
           cache: npm
           cache-dependency-path: frontend/package-lock.json
       - name: Install frontend dependencies
-        run: npm ci --prefix frontend
+        working-directory: frontend
+        run: npm ci
       - name: Build frontend
+        working-directory: frontend
         env:
           GITHUB_ACTIONS: true
           VITE_API_URL: https://stegokit.onrender.com/api
-        run: npm run build --prefix frontend
+        run: npm run build
       - name: Upload artifact
         uses: actions/upload-pages-artifact@v3
         with: