Add three new native modules (fswatch, sysinfo, udp) to the Wren CLI build system and module registry. Extend the io module with async file copy and move operations using libuv uv_fs_copyfile and uv_fs_rename, plus expose stat mtime/atime/ctime fields and stdin windowSize. Update the io.wren wrapper with File.write, File.copy, File.move static methods and corresponding foreign declarations. Add shebang lines to generator2.wren, merge_all_wren.wren, merge_docs.wren, and phonebook.wren scripts.
Add compiler support for calling async functions directly with `await fn(args)` syntax, automatically translating to `await fn.call(args)`. Introduce `create_merge` Makefile target for merging Wren source files. Include new `apps/generator.wren` source code generator using OpenRouter API, `apps/phonebook.wren` CLI phonebook with SQLite backend, and `apps/minitut.md` Wren tutorial reference. Update `example/await_demo.wren` with parameterized async functions, nested awaits, and expression usage. Fix JSON parsing in `example/openrouter_demo.wren` to strip markdown code fences. Document new await syntax in `manual/api/scheduler.html`.
