ci: add GitHub Pages deployment workflow

.github/workflows/deploy.yml

@@ -0,0 +1,49 @@
+name: Deploy to GitHub Pages
+
+on:
+  push:
+    branches: [master]
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+concurrency:
+  group: pages
+  cancel-in-progress: true
+
+jobs:
+  build-and-deploy:
+    runs-on: ubuntu-latest
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 22
+          cache: npm
+
+      - name: Copy firebase config
+        run: cp src/environments/firebaseConfig.example.ts src/environments/firebaseConfig.ts
+
+      - run: npm ci
+
+      - name: Build
+        run: npm run build
+
+      - name: Fix base href for GitHub Pages
+        run: sed -i 's|<base href="/">|<base href="/kanban2/">|g' dist/kanban2/browser/index.html
+
+      - name: Upload artifact
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: dist/kanban2/browser
+
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4