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()`.
Add MAX_PARAMETERS constant set to 16 and extend VM bytecode instructions CODE_CALL_11 through CODE_CALL_16 to support the new limit. Introduce compile-time error messages when parameter or argument count exceeds 16 in function definitions, method declarations, subscript calls, and regular method calls. Add new native fiber call stubs fn_call9 through fn_call16 and register them in the core initialization. Include comprehensive test coverage for 9-16 parameter functions and methods, plus error tests for exceeding the limit in all contexts.
