- Delete wren_io.c, wren_io.h, and io.wren source files
- Remove multi-arity print overloads and IO.read/IO.time methods
- Add System class with print, printAll, write, writeAll methods to core.wren
- Update all documentation examples and README to use System.print instead of IO.print
- Convert list() and map() compiler functions from if/do-while to do-while loops
- Remove redundant empty literal handling by breaking on right bracket/brace
- Add new test files for duplicate comma, duplicate trailing comma, and empty list/map with comma
- Expand newlines test to cover trailing comma and empty list/map cases
- Simplify trailing_comma tests by removing inline syntax error checks
- Update Test.fail() to handle variable arguments without kwargs
