feat(ci): deploy the docs site to home-main-2 (docs.punktfunk.unom.io)

docker.yml gains a deploy-docs job after the image pushes: scp
compose.production.yml to ~/punktfunk-docs on home-main-2, then
docker compose pull + up over SSH — the unom/website / unom/cms
deploy pattern, same DEPLOY_* secret set (unom-ci-deploy key). Docs
bind host port 3220; the docs.punktfunk.unom.io vhost lives in
unom/reverse-proxy (306d9c0).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

compose.production.yml

@@ -0,0 +1,11 @@
+# Production compose for the deployed punktfunk pieces — runs on home-main-2 under
+# ~/punktfunk-docs (synced there by .gitea/workflows/docker.yml's deploy job; pattern
+# follows unom/website + unom/cms). Caddy on home-reverse-proxy-1 serves
+# docs.punktfunk.unom.io -> home-main-2:3220 (vhost in unom/reverse-proxy).
+name: punktfunk-docs-prod
+services:
+  docs:
+    image: git.unom.io/unom/punktfunk-docs:latest
+    restart: unless-stopped
+    ports:
+      - "3220:3000"