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 ''.
Adds × delete button per row in both tables (desktop column +
mobile card header). Click → native <dialog> confirm modal with
Esc/backdrop-cancel, destructive red button, error inline.
Wires deleteAccount/deleteUser Server Actions calling the new
api-server routes; revalidatePath refreshes the list on success.
EditableCell input switches to text-base (16px) on phone (sm:text-[13px]
above 640px), preventing iOS Safari auto-zoom-on-focus that was
shifting the layout when the soft keyboard appeared.
