ci: add GitHub Actions deploy workflow

On push to main: builds Astro, deploys dist/ to reg.ru via rsync over SSH.
Requires DEPLOY_KEY, DEPLOY_HOST, DEPLOY_USER secrets.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.github/workflows/deploy.yml

@@ -0,0 +1,33 @@
+name: Deploy
+
+on:
+  push:
+    branches: [main]
+
+jobs:
+  deploy:
+    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
+
+      - name: Setup SSH key
+        run: |
+          mkdir -p ~/.ssh
+          echo "${{ secrets.DEPLOY_KEY }}" > ~/.ssh/deploy_key
+          chmod 600 ~/.ssh/deploy_key
+          ssh-keyscan -H ${{ secrets.DEPLOY_HOST }} >> ~/.ssh/known_hosts
+
+      - name: Deploy via rsync
+        run: |
+          rsync -avz --delete \
+            -e "ssh -i ~/.ssh/deploy_key -o StrictHostKeyChecking=no" \
+            dist/ \
+            ${{ secrets.DEPLOY_USER }}@${{ secrets.DEPLOY_HOST }}:~/www/randify.pro/