Bug: Creating category that already exists ends in blank screen

[ahatzz11]

Describe the bug
When making a category with a name that already exists the app doesn't tell you the error until after you make it, and then leaves you on a completely blank page which requires a manual refresh. This should probably be handled and displayed to the user in a nicer way - perhaps validation before hitting "Create Category". There's also no error if you try to re-make the failed category resulting in the blank screen again.

Note: This is basically a duplicate of #1576 which was sort of fixed in #1577, but I think there's still lots of room for improvement.

To Reproduce
Steps to reproduce the behavior:

1. Go to Categories
2. Create new category with existing name
3. Page reloads and gives you error with blank page behind it.
4. There are three options now:
   a. Happy path - new category name
   b. Click the X to close the modal, but you are now left on the blank page
   c. Click "Create category" again, nothing happens and you're left on the same blank page

Expected behavior
Ideally there would be input validation once you are done typing to show if it's a valid category name or not. If this isn't possible, then I'd expect a few things:

1. Not to be left on a completely blank screen
2. Re-clicking "Create category" should once again result in the same error instead of being put on a blank screen

What version of Maybe are you using?
Hosted

What operating system and browser are you using?
MacOS, Chrome

Screenshots / Recordings

CleanShot-001048.2025-01-05.at.20.36.59.mp4