Fix remote buzzer reconnect handling

[reloxx13]

Prerequisites checklist

• I have read the contributing guidelines.

What is the purpose of this pull request? (put an "x" next to an item)

• Documentation update
• Bug fix
• New feature
• Other, please explain:

What changes did you make? (Give an overview)

• remove the one-shot remote buzzer reachability probe in the browser client
• connect to the remote buzzer server directly via socket.io with reconnect enabled
• track connect, disconnect, and connect_error so the client state reflects the real connection

Is there anything you'd like reviewers to focus on?

• whether reconnect and disconnected-state handling behave correctly when the remote buzzer server is unavailable during page load and comes back later

AI used to create this Pull Request?

• AI was used to help implement the change.
• The resulting code change is limited to assets/js/remotebuzzer-client.js and updates only the client connection/reconnect behavior.
• Validation run for this change:
  • npm run eslint -- assets/js/remotebuzzer-client.js
  • npm run build:gulp