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)

docker-registry/docker-compose.yaml

@@ -40,4 +40,4 @@ services:
       - /srv/registry/data:/data
       - /srv/registry/registry.password:/auth/registry.password
     ports:
-      - 5000
+      - 127.0.0.1:5000:5000