Add foreign static methods `create_` and `delete_` to the Directory class in the Wren io module, backed by C implementations using `uv_fs_mkdir` and `uv_fs_rmdir` with proper error handling via `schedulerResumeError`. Refactor existing `Directory.list` and `File.delete` to use the new `Scheduler.await_` helper instead of manually calling `runNextScheduled_`, and rename `ensurePath_` to `ensureString_` for consistency across both classes. Introduce a new test file `create_delete.wren` that validates directory creation, existence checks, and deletion on both POSIX and Windows platforms.
Replace the generic "Do not edit" comment in all five `.wren.inc` files with a
more informative preamble that explicitly names the source `.wren` file and the
`util/wren_to_c_string.py` generator script, and update the script's own
`PREAMBLE` template accordingly.
Add foreign class File with static open, read, size methods and instance methods for close, size, readBytes. Implement async file operations using libuv callbacks that resume fibers on completion. Introduce schedulerResumeError and resumeError_ to propagate I/O errors as fiber errors. Add setExitCode to CLI vm for runtime error exit handling. Bump MAX_METHODS_PER_CLASS from 2 to 9 to accommodate new File methods.
Introduce a new scheduler module with fiber-based cooperative multitasking, including native bindings for resume operations and a Wren class for scheduling callables. Refactor the existing timer module and CLI code to use a centralized built-in module registry in modules.c, replacing direct includes of timer.h and timer.wren.inc. Update Xcode project and Makefile to compile the new scheduler.c, modules.c, and their generated .wren.inc sources.
