Initialize Cargo workspace with wraith-core, wraith, and wraith-napi crates

- Workspace root Cargo.toml with three crate members
- wraith-core: library with feature flags (tls, iroh, acme), core deps (russh, tokio, tracing, anyhow, thiserror, tokio-util), module skeleton (transport, client, server, auth, socks5, error)
- wraith: binary crate depending on wraith-core with clap derive
- wraith-napi: cdylib crate depending on wraith-core, napi, napi-derive
- .gitignore for target/ and node_modules/

crates/wraith-core/src/lib.rs

@@ -0,0 +1,6 @@
+pub mod transport;
+pub mod client;
+pub mod server;
+pub mod auth;
+pub mod socks5;
+pub mod error;