refactor!: rebrand wraith to alknet

Rename all crates, CLI commands, constants, type names, doc comments,
and documentation from wraith to alknet. Includes wire-protocol changes:
ALPN wraith-ssh -> alknet-ssh, reserved destination prefix wraith- ->
alknet-, SSH auth username wraith -> alknet.

crates/alknet-napi/src/lib.rs

@@ -0,0 +1,29 @@
+//! # alknet-napi
+//!
+//! Node.js native addon for [Alknet](https://git.alk.dev/alkdev/alknet) via napi-rs.
+//! Exposes `connect()` and `serve()` functions for programmatic SSH tunnel creation.
+//!
+//! > **Alpha software.** The NAPI interface may change between versions.
+//!
+//! # Quick example (Node.js)
+//!
+//! ```js
+//! const { connect, serve } = require('alknet-napi');
+//!
+//! // Client: open a duplex SSH stream
+//! const stream = await connect({
+//!   server: "example.com:22",
+//!   transport: "tcp",
+//!   identity: "/path/to/key",
+//! });
+//! await stream.write(Buffer.from("hello"));
+//! const data = await stream.read(1024);
+//! await stream.close();
+//! ```
+
+#[allow(unused_imports)]
+#[macro_use]
+extern crate napi_derive;
+
+mod connect;
+mod serve;