Incorrect suggestions after applying fix for `WiFi -> Wi-Fi`

## Description

When I write the sentence "The WiFi at the office was slow today." on writewithharper.com I get the suggestion to replace `WiFi` with `Wi-Fi` which seems fine, but then it starts flagging `Wi` as a typo and the `Fi at` as a potential misspelling of `Fiat` which are both false positives in that context.

## Resources

Wi-Fi appears to be the [correct way of writing this](https://en.wikipedia.org/wiki/Wi-Fi) so I don't know what Harper could do here but it sure is annoying

## Screenshots

Initial sentence


Incorrect suggestions after the edit is applied


Start by reproducing the sentence on writewithharper.com and compare the initial suggestions with the results after applying WiFi → Wi-Fi. Trace the Rust checker’s replacement and subsequent tokenization or spell-checking behavior, then add a regression test for this sentence if the relevant test area is found. Done means Wi-Fi is accepted without separate false positives for Wi or Fi at.

Written by the indexing model from the issue text.