feat(js): rewrite in JavaScript as a browser app

.github/workflows/deploy.yml

@@ -0,0 +1,49 @@
+name: Deploy to GitHub Pages
+
+on:
+  push:
+    branches: [main]
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+concurrency:
+  group: pages
+  cancel-in-progress: false
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+      - uses: actions/setup-node@v7
+        with:
+          node-version: '24'
+          cache: 'npm'
+      - run: npm ci
+      - run: npm run lint
+      - run: npm test
+
+  build-deploy:
+    needs: test
+    runs-on: ubuntu-latest
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    steps:
+      - uses: actions/checkout@v7
+      - uses: actions/setup-node@v7
+        with:
+          node-version: '24'
+          cache: 'npm'
+      - run: npm ci
+      - run: npm run build
+      - uses: actions/configure-pages@v6
+      - uses: actions/upload-pages-artifact@v5
+        with:
+          path: dist
+      - id: deployment
+        uses: actions/deploy-pages@v5