Function get_platform_vfs 

pub fn get_platform_vfs() -> Box<dyn Vfs + Send + Sync>

Get the platform-default VFS instance.

• Linux with io-uring feature: Tries UringVfs first for kernel-async I/O, falls back to NativeVfs if io_uring is unavailable (old kernel, container).
• Other native: Returns NativeVfs (tokio::fs)
• WASM: Returns WorkerOpfsVfs backed by a Web Worker