ci: add Gitea Actions deploy workflow

Auto-deploy to VPS on push to main via host runner.

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

.gitea/workflows/deploy.yml

@@ -0,0 +1,19 @@
+name: Deploy
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  deploy:
+    runs-on: host
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Deploy container
+        run: |
+          rsync -a --delete ${{ gitea.workspace }}/ /opt/redunits/www/
+          cd /opt/redunits/www
+          docker compose up -d --build