fix: Refine WebSocket connection management logic

[bretamerman]

adds guards to the heartbeat interval to prevent a send with an invalid socket updates connection timeout to use the connection timeout option uses clearTimeout for setTimeout and clearInterval for setInterval

[bretamerman]

Had a bot that was running the other day randomly die on me. Stack trace shows it failed on this line, this.send({ type: "Ping", data: +new Date() });.

2026-03-18 11:35:28.317 [error]: Client error occurred: Received network error or non-101 status code.
2026-03-18 11:35:29.775 [error]: Uncaught Exception: Sent before connected. {
  "stack": "InvalidStateError: Sent before connected.\n    at new DOMException (node:internal/per_context/domexception:53:5)\n    at WebSocket.send (node:internal/deps/undici/undici:12680:17)\n    at EventClient.send (file:///Users/.../node_modules/revolt.js/lib/events/EventClient.js:123:22)\n    at Timeout._onTimeout (file:///Users/.../node_modules/revolt.js/lib/events/EventClient.js:75:22)\n    at listOnTimeout (node:internal/timers:614:17)\n    at processTimers (node:internal/timers:549:7)"
}