infra: 2026-10-26 version audit, upgrades, UniFi re-removal

- Synapse v1.163.2, MAS 1.27.1, Traefik v3.7, node-exporter v1.12.1 (all
  nodes), cadvisor -> ghcr.io v0.60.6, alertmanager-receiver 2026.9.23,
  Gitea 1.26.4, Jellyfin 12.3, Seerr v3.5.1
- Watchtower -> nickfedor/watchtower fork, twice daily (04:00/16:00)
- Monitoring legacy node-exporter gated behind a compose profile
- unifi-os-server on .100 removed again; compose file renamed so it
  cannot be revived
- CLAUDE.md: Known Issues #40-43, service tree updates

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NQhgEUqcaV4WM2S4hfXgHD

compose/hf-pdocker-01/matrix/docker-compose.yml

@@ -2,7 +2,7 @@ services:
   synapse:
     # 2026-08-20: matrixdotorg repo is abandoned (froze at 1.148.0); upstream is now element-hq.
     # Pinned deliberately so the running version is visible in the file - bump manually.
-    image: ghcr.io/element-hq/synapse:v1.159.0
+    image: ghcr.io/element-hq/synapse:v1.163.2
     container_name: synapse
     restart: unless-stopped
     environment: