fix(api): UI crash with TypeError: i.map is not a function

[psychedelicious]

Summary

This pops up every now and then and I could never figure it out. A user figured it out in #6936. The cause is appending a query string to the app URL.

For example:

http://127.0.0.1:9090/?__theme=dark

The query string breaking the static file serving, which prevents our translations from loading correctly. Instead of the JSON translations, FastAPI sends the index HTML page. The UI then errors when attempting to parse the translation JSON.

The query string ?__theme=dark is used by Gradio to force dark mode. I believe the users with this issue are doing the same thing the user in #6936 did (just change the port number on an existing bookmark) or their browser history/bookmark includes the query string.

Though this is technically a user-caused problem (we cannot prevent the user from using a malformed URL), we can work around it. When query string is used on the root path, we can redirect the browser to the root path without the query string.

This is done via very simple middleware.

Related Issues / Discussions

Closes #6696
Closes #6817
Closes #6828
Closes #6936
Closes #6983

QA Instructions

Do a prod build of the UI and navigate to http://127.0.0.1:9090/?__theme=dark

On main, we expect the UI to error. On this PR, we expect to be redirected to http://127.0.0.1:9090/ and not error.

Merge Plan

n/a

Checklist

• The PR has a short but descriptive title, suitable for a changelog
• Tests added / updated (if applicable)
• Documentation added / updated (if applicable)