Finalizes the hash and returns the digest. The hasher cannot be reused after this.
Feed a JS-owned buffer into the hash - zero-copy via bun:ffi's ptr().
Feed a chunk already referenced by a raw pointer/length (e.g. a
Rust-owned NativeChunk) into the hash - no copy at all, not even the
ptr() lookup update() needs for a JS-owned buffer.
Incremental sha256 hasher backed by a Rust
cdylibviabun:ffi.update()passes a raw pointer into the caller's buffer straight to the synchronous Rust FFI call - a zero-copy handoff for a JS-ownedUint8Array, or a pure pointer passthrough for an already Rust-owned buffer (updatePointer()).