Ominous security warning when deployed via Heroku - Chrome labels as "dangerous"

Feedback from someone, and I was able to verify on my end too:

> Hey Sterling! I tried opening the Gavel link that was sent to my email and there's a massive security warning that pops up. Is that normal...?


To proceed, one needs to click details and then "continue to site" or similar.

Gets there just fine, but then still shows "dangerous" label next to the URL:


Some additional details when clicking the warning label:


Based on https://stackoverflow.com/questions/78442495/why-do-i-get-dangerous-site-warning-for-my-heroku-app-even-after-i-registered, seems that doing [google site verification](https://support.google.com/webmasters/answer/9008080?hl=en) and waiting a few days may address the issue.

Here's what I shared with the judges afterwards:
> An email with subject line "Welcome to Gavel!" should have arrived. When you click the link, Chrome will probably label it as "dangerous" (this can be ignored in this case, and I know [how to address it for later](https://stackoverflow.com/questions/78442495/why-do-i-get-dangerous-site-warning-for-my-heroku-app-even-after-i-registered)). Click "details" and then click the hyperlink to proceed. Gavel is a pairwise comparison judging system. Once you're there, you'll read over the first question, click continue, read the next question, and choose which one you like better. Reach out to me if you want to get other topics/questions added.