Convert project to TypeScript; add workflow to build with Vite then publish to GH Pages.

.github/workflows/build.yml

@@ -0,0 +1,39 @@
+name: Build Vite
+
+on:
+  push:
+    branches:
+      - master
+  workflow_dispatch:
+
+permissions:
+  contents: write
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    
+    strategy:
+      matrix:
+        node-version: [24.x]
+    
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v4
+        with:
+          node-version: ${{ matrix.node-version }}
+
+      - name: Install dependencies & build
+        run: |
+          npm ci
+          npm run build
+
+      - name: Deploy
+        uses: peaceiris/actions-gh-pages@v4
+        with:
+          publish_dir: ./dist
+          github_token: ${{ secrets.GITHUB_TOKEN }}