ci: add self-deploy workflow via workflow_dispatch

Allows triggering a deploy via Gitea API. SSHes to Unraid to pull
latest image and restart the nanobot container.

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

.github/workflows/deploy.yml

@@ -0,0 +1,16 @@
+name: Deploy Nanobot
+
+on:
+  workflow_dispatch:
+
+jobs:
+  deploy:
+    runs-on: [self-hosted, linux-amd64]
+    timeout-minutes: 5
+    steps:
+      - name: Pull latest image and restart container
+        env:
+          UNRAID_PASS: ${{ secrets.UNRAID_PASS }}
+        run: |
+          sshpass -p "$UNRAID_PASS" ssh -o StrictHostKeyChecking=no -p 23 root@192.168.1.50 \
+            "docker pull git.wylab.me/wylab/nanobot:latest && docker restart nanobot"