ci: add GitHub Actions workflow to build and deploy to GitHub Pages

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

superpowers/.github/workflows/deploy.yml

@@ -0,0 +1,46 @@
+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: true
+
+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 test
+
+      - 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

superpowers/vite.config.ts

@@ -3,6 +3,7 @@ import { defineConfig } from "vite";
 import react from "@vitejs/plugin-react";
 
 export default defineConfig({
+  base: "/try-superpowers/",
   plugins: [react()],
   test: {
     globals: true,