web: use canonical tailwind class names
mechanical sweep of everything the new lint rule can fix on its own:
rounded -> rounded-sm, flex-grow -> grow, px-2 py-2 -> p-2, arbitrary px
values onto the spacing scale (size-[26px] -> size-6.5), and v4 variant
forms ([&>*]: -> *:).
left alone: max-w-screen-* keeps its breakpoint linkage, and the
text-*/leading-* pairs that collapse into typography-* utilities are a
design-system call, not a rename.
Signed-off-by: eti <eti@eti.tf>