Public website (writewithharper.com) fails to load. Stuck on 'Loading Harper's grammar engine' Browser becomes unresponsive (Chrome/Firefox/Safari on Mac)

**Describe the bug**
https://writewithharper.com fails to load in any browser on my MacOS machine, running MacOS Tahoe 26.5.1
They all show

At which point, they become unresponsive. After some time, Chrome displays the message:

and then finally:

**To Reproduce**
Steps to reproduce the behaviour:
1. Visit 'https://writewithharper.com/' on a machine running MacOS Tahoe, using any browser
2. Notice the 'Try harper' UI fails to load
3. Notice that the browser becomes unresponsive and none of the links work
4. See error

**Screenshots**
See above

**Platform**
MacOS Tahoe 26.5.1 on a MBP M5 Max. Freezes the latest versions of all browsers (Chrome, Safari, Firefox)