security: remove hardcoded secrets, drop unneeded privileged mode, restrict internal-only ports to localhost

- watchtower: move Telegram token/chat ID to .env instead of plaintext in compose
- plex: remove stale/dead PLEX_CLAIM token
- uptime-kuma: mount docker.sock read-only (only needs to read container state)
- home-assistant: drop privileged: true (no device passthrough configured)
- glances: drop privileged: true, bind dashboard port to 127.0.0.1
- couchdb, docker-registry, leafweb: bind ports to 127.0.0.1 (proxy/localhost-only access confirmed, no direct LAN clients)

uptime-kuma/docker-compose.yaml

@@ -5,7 +5,7 @@ services:
     restart: unless-stopped
     volumes:
       - /srv/uptime-kuma/data:/app/data
-      - /var/run/docker.sock:/var/run/docker.sock
+      - /var/run/docker.sock:/var/run/docker.sock:ro
     environment:
       - TZ=America/New_York
       - VIRTUAL_HOST=uptime.kolpacksoftware.com