Feat: Detect Steam overlay availability

[st14n]

I've got this to work using these few small changes.

On my electron app I used something like

let steamInitialized = false;
let steamOverlayEnabled = null;

try {
    console.log("Initializing Steam with app ID: XXX");
    const steamworks = require('steamworks.js');
    global.steamClient = steamworks.init(XXX);
    require('steamworks.js').electronEnableSteamOverlay();
    console.log("Steam initialized successfully");

    setTimeout(() => {
        try {
            const overlayEnabled = steamworks.isOverlayEnabled();
            steamOverlayEnabled = overlayEnabled;
            console.log('Steam overlay enabled (delayed):', overlayEnabled);
        } catch (e) {
            console.error('Failed to query overlay status:', e);
        }
    }, 3000);

    steamInitialized = true;
} catch (e) {
    console.error("Failed to initialize Steam:", e.message);
    steamInitialized = false;
}

Key was waiting - in this example 3 seconds - before checking enabled status.