feat: deploy web app to GitHub Pages

.github/workflows/pages.yml

@@ -0,0 +1,64 @@
+# Build and deploy the web app to GitHub Pages.
+# Enable in repo: Settings → Pages → Source: GitHub Actions.
+# Site URL: https://<owner>.github.io/<repo>/
+
+name: Deploy Web App to GitHub Pages
+
+on:
+  push:
+    branches: ["main", "master"]
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+concurrency:
+  group: "pages"
+  cancel-in-progress: false
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: "lts/*"
+          cache: "npm"
+
+      - name: Install root dependencies
+        run: npm ci
+
+      - name: Prepare web app (index + skills)
+        run: npm run app:setup
+
+      - name: Install web-app dependencies
+        run: cd apps/web-app && npm ci
+
+      - name: Build web app for GitHub Pages
+        run: cd apps/web-app && npm run build
+        env:
+          VITE_BASE_PATH: /${{ github.event.repository.name }}/
+
+      - name: SPA fallback for client-side routes
+        run: cp apps/web-app/dist/${{ github.event.repository.name }}/index.html apps/web-app/dist/${{ github.event.repository.name }}/404.html
+
+      - name: Upload Pages artifact
+        uses: actions/upload-pages-artifact@3
+        with:
+          path: apps/web-app/dist
+
+  deploy:
+    needs: build
+    runs-on: ubuntu-latest
+    environment:
+      name: github-pages
+      url: ${{ steps.deploy.outputs.page_url }}
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deploy
+        uses: actions/deploy-pages@4