feat(ci): Add demo system deployment and document it in the README

The release flow now also deploys to demo.freundebuch.datenknoten.me.
The README gets a "Try the Demo" section with the demo account
credentials from the seed script and a note that all demo data is
reset daily at 06:00 UTC.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: enko

.github/workflows/release.yml

@@ -329,7 +329,7 @@ jobs:
           mkdir -p ~/.ssh
           echo "[node4.datenknoten.me]:820 ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAILOtQWdKnvQYP0gA5tnyYrTt+uGJDek3YGWSHi2M6f35" >> ~/.ssh/known_hosts
 
-      - name: Deploy via SSH
+      - name: Deploy Production System
         env:
           DEPLOY_HOST: node4.datenknoten.me
           DEPLOY_PORT: 820
@@ -338,6 +338,15 @@ jobs:
         run: |
           ssh -p "${DEPLOY_PORT}" "${DEPLOY_USER}@${DEPLOY_HOST}" /home/deploy-freundebuch/deploy.sh "${VERSION}"
 
+      - name: Deploy Demo System 
+        env:
+          DEPLOY_HOST: demo.freundebuch.datenknoten.me
+          DEPLOY_PORT: 820
+          DEPLOY_USER: ${{ secrets.DEPLOY_SSH_USER }}
+          VERSION: ${{ needs.release.outputs.new_release_version }}
+        run: |
+          ssh -p "${DEPLOY_PORT}" "${DEPLOY_USER}@${DEPLOY_HOST}" /home/deploy-freundebuch/deploy.sh "${VERSION}"
+
       - name: Send deployment notification
         if: success()
         env:

README.md

@@ -10,6 +10,17 @@ A self-hostable web application for relationship management. Think of it as your
 - **Self-hostable** — run it on your own server, keep full control over your data
 - **Multi-user ready** — works great for families or households sharing an address book
 
+## Try the Demo
+
+Want to poke around before setting anything up? There's a public demo at [demo.freundebuch.datenknoten.me](https://demo.freundebuch.datenknoten.me).
+
+Log in with the demo account, which comes pre-filled with sample friends, circles, and encounters:
+
+- **Email:** `demo@freundebuch.app`
+- **Password:** `DemoPassword123!`
+
+It's a sandbox, so experiment as much as you like. Just don't store anything you want to keep: **all demo data is reset daily at 06:00 UTC**.
+
 ## Quick Start
 
 ```bash