wit URL API

Client-side MemoryBackend showcase: /tree, /ls, /cat return the same plaintext as the CLI. Path is a query param. Auth via Authorization (preferred) or ?token= (leaks — avoid).

Ready. Routes run in-page via wit-snapshot wasm (open/list/read).

Pure static hosts cannot execute wasm for curl — use the Pages Function / worker host adapter for text/plain. See docs/adr/0005-url-api-howto.md.