Fix Broken Referral Tracking Parameters

Our referral links are live yet not crediting sign-ups because the tracking parameters inside each link are broken. I need a JavaScript-savvy developer to dive into the current codebase, locate the faulty parameter logic, and restore accurate tracking end-to-end within one week.

Here’s what I expect:
• Audit the link-generation script and pinpoint why parameters are malformed or missing.
• Repair the JavaScript that appends those parameters so every referral URL carries the correct data.
• Test across typical user flows—desktop, mobile, and any deep-link redirections—to confirm referrals are logged correctly in our analytics.
• Deliver the updated code, a brief change log, and quick setup notes so I can deploy immediately.

The codebase is plain JavaScript (no framework), version-controlled in Git. I’ll grant repo access as soon as we start. If you’ve squashed similar referral bugs before, I’d love to see a short example or explanation.