fix(tracking): await plausible callback to confirm event sent

[mohanadft]

Summary

• Changes window.plausible(...) call to use the callback option wrapped in a Promise, then await it
• This ensures the HTTP request to Plausible actually completes before the handler returns, rather than fire-and-forget
• Debug logging kept in place from previous PR

Why

The previous fire-and-forget call may have been cancelled if Qgiv tore down the embed or caused any page state change immediately after firing QGIV.donationComplete. Awaiting the callback guarantees the event is confirmed sent.

Test

1. Go to https://techforpalestine.org/donate?variant=qgiv
2. Open DevTools console
3. Make a donation
4. Confirm you see [T4P DEBUG] plausible await resolved — event confirmed sent
5. Check Plausible dashboard for the event

[cloudflare-workers-and-pages]

Deploying website with    Cloudflare Pages

Latest commit:	cc6aab9
Status:	✅  Deploy successful!
Preview URL:	https://64ccb640.website-aun.pages.dev
Branch Preview URL:	https://fix-plausible-await-callback.website-aun.pages.dev

View logs