The lowerer matched GROUP BY keys with the polymorphic (=) on an
Ast.expr, and the tree-walker tested a comparison's result with (=) on
an Ast.value. Both walk the runtime representation of a type whose
owner is Ast, and on an expression tree that representation includes a
float: a nan literal compares unequal to itself, so a GROUP BY key
holding one could never match.

Ast now exposes equal_value -- the engine core's Catalog.Value.equal,
which compares floats by bit pattern -- and equal_expr, spelled out node
by node over the whole query tree so a literal goes through equal_value
and a new constructor is a compile error here rather than a silent
hole.

The nox- prefix existed only because the bare name tty is taken on
central opam. console is free there and says what the library is:
inline styled terminal output rather than a full-screen TUI. Rename
the opam packages (nox-tty -> console, nox-tty-eio -> console-eio),
the modules (Tty -> Console, Tty_eio -> Console_eio), the C stub
namespace, the repository directory (ocaml-tty -> ocaml-console) and
the bundled Claude skill, and update every in-tree consumer. The
tangled repo must be renamed to ocaml-console to match before the
next monopam push.

These packages are published only to the opam overlay, not the public
opam-repository. Without the repo-add line a reader who runs opam install
gets nothing and has to hunt down the overlay URL by hand.