feat: add real Stripe integration, e2e tests, and Pi deployment

Replace documentation-only repo with working code:

- Stripe integration: webhook handler (8 event types), billing API
  (customers, checkout, payments, subscriptions, invoices)
- Express API server with health endpoint, structured logging
- E2E tests (Playwright): health, webhook signature verification,
  billing API validation
- Unit tests: webhook event handler coverage for all event types
- Pi deployment: deploy.sh (rsync + systemd), NGINX load balancer
  across Pi cluster, Docker support
- CI/CD: test workflow, Pi deploy workflow, updated auto-deploy
  and self-healing to run real tests before deploying
- Move resume docs to docs/ to separate code from documentation

https://claude.ai/code/session_01Mf5Pg82fV6BTRS9GnpV7nr

.github/workflows/deploy-pi.yml

@@ -0,0 +1,57 @@
+name: Deploy to Pi
+
+on:
+  workflow_dispatch:
+  push:
+    branches: [main, master]
+    paths:
+      - 'src/**'
+      - 'package.json'
+      - 'Dockerfile'
+      - 'deploy/**'
+
+jobs:
+  test:
+    name: Run Tests First
+    uses: ./.github/workflows/test.yml
+
+  deploy:
+    name: Deploy to Raspberry Pi Nodes
+    runs-on: ubuntu-latest
+    needs: test
+    if: github.ref == 'refs/heads/main' || github.ref == 'refs/heads/master'
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup SSH key
+        run: |
+          mkdir -p ~/.ssh
+          echo "${{ secrets.PI_SSH_PRIVATE_KEY }}" > ~/.ssh/id_ed25519
+          chmod 600 ~/.ssh/id_ed25519
+          ssh-keyscan -H ${{ secrets.PI_HOST_1 }} >> ~/.ssh/known_hosts 2>/dev/null || true
+          ssh-keyscan -H ${{ secrets.PI_HOST_2 }} >> ~/.ssh/known_hosts 2>/dev/null || true
+          ssh-keyscan -H ${{ secrets.PI_HOST_3 }} >> ~/.ssh/known_hosts 2>/dev/null || true
+
+      - name: Create .env for deployment
+        run: |
+          cat > .env <<EOF
+          STRIPE_SECRET_KEY=${{ secrets.STRIPE_SECRET_KEY }}
+          STRIPE_PUBLISHABLE_KEY=${{ secrets.STRIPE_PUBLISHABLE_KEY }}
+          STRIPE_WEBHOOK_SECRET=${{ secrets.STRIPE_WEBHOOK_SECRET }}
+          PORT=3000
+          NODE_ENV=production
+          PI_HOST_1=${{ secrets.PI_HOST_1 }}
+          PI_HOST_2=${{ secrets.PI_HOST_2 }}
+          PI_HOST_3=${{ secrets.PI_HOST_3 }}
+          PI_USER=${{ secrets.PI_USER }}
+          PI_DEPLOY_PATH=/opt/blackroad
+          PI_SSH_KEY=~/.ssh/id_ed25519
+          EOF
+
+      - name: Deploy to Pis
+        run: bash deploy/pi/deploy.sh
+
+      - name: Cleanup
+        if: always()
+        run: rm -f .env ~/.ssh/id_ed25519