feat(syslog): set-up help on the page, port 5514 published, Docker-hidden senders called out (#6003)

The Syslog page says where to send (this server, its port and protocols) and
where the setting is on Synology, QNAP, TrueNAS, OpenWrt, UniFi and rsyslog,
open until a device sends. A sender whose address is on Steward's own
container network (Swarm ingress publishing hides the real sender) is
flagged, with the host-mode ports to publish instead. compose files and the
Dockerfile publish 5514/udp and /tcp; docs/plugins/syslog.md describes the
plugin and the deploy.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

README.md

@@ -53,7 +53,7 @@ cp .env.example .env
 docker compose -f compose.deploy.yml up -d
 ```
 
-Open `http://<server>:5000` and create the admin account on first run.
+Open `http://<server>:5000` and create the admin account on first run. Devices send syslog to `<server>:5514` (UDP or TCP); see `docs/plugins/syslog.md`.
 
 **Update to the latest dev build:**
 
@@ -124,5 +124,6 @@ See `docs/plugins/` for a full plugin development guide.
 | `docs/plugins/writing-a-plugin.md` | Step-by-step plugin development guide |
 | `docs/plugins/traefik.md` | Traefik plugin: config, metrics, alert rule examples |
 | `docs/plugins/prometheus.md` | Prometheus plugin: scraping any /metrics endpoint, how series are stored, the Fabled Archives recipe |
+| `docs/plugins/syslog.md` | Syslog plugin: sources, patterns and alerts, publishing port 5514 (host mode under Swarm) |
 | `docs/plugins/prometheus-widgets.md` | Prometheus widget templates: writing, sharing and copying one in, every block, the format reference |
 | `docs/reference/code-map.md` | Where every key function, model, and route lives in the codebase |