WebSocket connection fails on Node.js 24 — built-in WebSocket doesn't support auth headers

[israelkalush-lgtm]

Description

The SDK's ReconnectingWebSocket (core/websocket/ws.js) uses getGlobalWebSocket() which prefers Node's built-in WebSocket (available since Node 22+) over the ws package. However, Node's built-in WebSocket does not support custom headers on connection, which means the Authorization: Bearer <token> header is never sent. The server returns 403 and the connection closes immediately.

Environment

• Node.js v24.14.0
• agentmail SDK v0.2.21
• macOS (Apple Silicon)

Steps to reproduce

1. Install SDK on Node 24
2. Call client.websockets.connect({ authToken: token })
3. WebSocket connects but immediately closes with code 1000/1006

Root cause

In core/websocket/ws.js, getGlobalWebSocket() checks typeof WebSocket !== "undefined" first. On Node 24, this is true (built-in), so the ws package is never used. But Node's built-in WebSocket cannot pass auth headers.

Workaround

Swap the check order to prefer ws on Node:

const getGlobalWebSocket = () => {
    if (index_js_1.RUNTIME.type === "node") {
        return ws_1.WebSocket;
    }
    else if (typeof WebSocket !== "undefined") {
        return WebSocket;
    }
    return undefined;
};

Suggested fix

Always prefer the ws package when running in a Node environment, since it supports headers. Fall back to the built-in WebSocket only in browser/Deno/Bun environments.