Summary

Implement the Preview 3 draft wasi:filesystem package, including path resolution and preopen behavior, on top of the async component foundation.

Parent tracking issue: #70
Suggested implementation order: 9 / 14

References

• https://github.com/WebAssembly/WASI/blob/main/docs/Preview2.md
• https://github.com/WebAssembly/wasi-filesystem/tree/v0.3.0-rc-2025-09-16
• https://github.com/WebAssembly/wasi-filesystem/blob/v0.3.0-rc-2025-09-16/imports.md
• https://github.com/WebAssembly/wasi-filesystem/blob/v0.3.0-rc-2025-09-16/path-resolution.md
• https://github.com/WebAssembly/wasi-filesystem/blob/v0.3.0-rc-2025-09-16/wit-0.3.0-draft/world.wit
• https://github.com/WebAssembly/wasi-filesystem/blob/v0.3.0-rc-2025-09-16/wit-0.3.0-draft/types.wit
• https://github.com/WebAssembly/wasi-filesystem/blob/v0.3.0-rc-2025-09-16/wit-0.3.0-draft/preopens.wit

Acceptance criteria

• The wasi:filesystem draft interfaces instantiate through the Preview 3 host binding scaffolding on native, web, and node backends.
• Node support is provided through JS interop host adapters rather than node:wasi.
• Focused tests cover representative preopen, metadata, directory, and path-resolution flows against the RC WIT surface.