fix(ocaml-tty,ocaml-wire): fix compilation errors from previous agent run

- tree.ml/mli: rename type 'a t → type 'a node to avoid conflict with
abstract type t (renderable tree); update of_tree and v signatures
- wire_c.ml: fix rank-2 polymorphism in emit_schema_tests by using
let pr fmt = Fmt.pf ppf fmt in (syntactic value, can be generalized)
instead of let pr = Fmt.pf ppf in (application, weak type variable)
- fuzz_tty.ml, test_table.ml, debug_progress.ml: update callers to use
Panel.v, Table.v, Progress.v after create → v rename