Add OnlyOffice integration for Seafile

- seafile/onlyoffice.yml: OnlyOffice Document Server 8.1 with JWT auth
- Expose on 127.0.0.1:6233, proxied via Caddy at office.alogins.net
- Caddyfile: add office.alogins.net → localhost:6233
- JWT secret stored in Vaultwarden (ONLYOFFICE_JWT_SECRET)
- seahub_settings.py configured inside container with ENABLE_ONLYOFFICE=True

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

Caddyfile

@@ -81,6 +81,10 @@ docs.alogins.net {
 	reverse_proxy localhost:8078
 }
 
+office.alogins.net {
+	reverse_proxy localhost:6233
+}
+
 vw.alogins.net {
 	reverse_proxy localhost:8041
 }