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/

Cargo.toml

@@ -0,0 +1,7 @@
+[workspace]
+members = [
+    "crates/wraith-core",
+    "crates/wraith",
+    "crates/wraith-napi",
+]
+resolver = "2"