Fix webhooks being sent twice due to duplicate frontend calls
Updated the assistant confirmation dialog so the next signer is always
visible (if dictate is enabled). Because if the form is invalid (due to
no name) there is no visual queue that the form is invalid (since it's
hidden)
## Notes
Didn't bother to remove the weird assistants form since it currently
works for now
## Tests
- Currently running locally
- Tested webhooks via network tab and via webhook.site
## Description
Currently there are various z-index values that are causing:
- Toasts to be placed behind dialog blur background
- Menu being cropped off by header
## Changes Made
- Revert `z-[1000]` back to `z-50` for the header (not exactly sure why
it was bumped)
- Refactor z-indexes over 9000 to start from 1000
- Ensure z-index of toast is higher than dialog
