Replace the global `io` singleton object with a static `IO` class, moving the `write` native from the instance to the metaclass. Update all benchmark, example, and test files to use `IO.write()` instead of `io.write()`.
The compiler previously required a TOKEN_LINE after each statement in a block,
causing parse failures for files missing a final newline. Changed consume() to
match() with conditional break, and added a test case for no-trailing-newline
files.