feat: initial theme scaffold

- Repo metadata: theme.toml, README, Apache-2.0 license
- Hugo defaults: vi language, post permalinks, taxonomies, paginate, TOC config
- exampleSite skeleton with themesDir wiring
- CI: Hugo build + Pagefind index + Pages deploy
- Pagefind devDependency in package.json (Dependabot weekly)
- vi i18n strings, default archetype
- Empty layouts/_partials/_markup/_shortcodes directories ready for Phase 3

.github/workflows/pages.yml

@@ -0,0 +1,63 @@
+name: Build and deploy exampleSite
+
+on:
+  push:
+    branches: [main]
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+concurrency:
+  group: pages
+  cancel-in-progress: true
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    env:
+      HUGO_VERSION: 0.154.0
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          submodules: recursive
+          fetch-depth: 0
+
+      - name: Setup Hugo (extended)
+        uses: peaceiris/actions-hugo@v3
+        with:
+          hugo-version: ${{ env.HUGO_VERSION }}
+          extended: true
+
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: npm
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Build site
+        working-directory: exampleSite
+        run: hugo --gc --minify --baseURL "https://tiennm99.github.io/tsuki/"
+
+      - name: Build Pagefind index
+        run: npx pagefind --site exampleSite/public
+
+      - name: Upload artifact
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: exampleSite/public
+
+  deploy:
+    needs: build
+    runs-on: ubuntu-latest
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    steps:
+      - id: deployment
+        uses: actions/deploy-pages@v4