feat: add tile glow, dynamic font sizing, and GitHub Pages deployment (Epic 5, Stories 5.1-5.3)

- Add box-shadow glow effect on tiles with value 128+
- Dynamic font sizing already implemented in Epic 4 responsive work (Story 5.2 = no-op)
- Set Vite base path to /try-bmad/ for GitHub Pages
- Add GitHub Actions workflow for automated deploy on push to main
- Production bundle 22.4KB gzipped (under 50KB target)

.github/workflows/deploy.yml

@@ -0,0 +1,40 @@
+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:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: npm
+      - run: npm ci
+      - run: npm run build
+      - uses: actions/upload-pages-artifact@v3
+        with:
+          path: dist
+
+  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