Native <dialog> in iOS Safari (and a few other browsers) doesn't
prevent the page underneath from scrolling when the user scrolls
inside the dialog or near its edges. Save and restore body overflow
on open/close so the background stays put. Stays correct for stacked
dialogs because we save the previous value rather than blanket-reset
to ''.
api-server gets /create-acc-data and /create-user-data POST routes
that INSERT into the respective tables with required-field validation.
Frontend adds an 'Add' button next to Refresh in each table head;
opens a native <dialog> form with all fields. Inputs use 16px font on
phone (sm:text-[13px] desktop) so iOS doesn't auto-zoom.
A small form-dialog-shell helper centralizes the modal chrome,
field label, and input class so create-account-dialog and
create-user-dialog stay focused on their fields and validation.
