Add top-level README.md with alpha status warning, quick start guide,
architecture overview, feature flags, transport modes, auth docs, and
Node.js API examples.
Add dual LICENSE-MIT and LICENSE-APACHE files.
Add comprehensive crate-level and module-level rustdoc to all three
crates (wraith-core, wraith, wraith-napi) and all public modules
(transport, client, server, auth, socks5, error). Add doc comments to
key public types (Transport, TransportAcceptor, ConnectOptions,
ClientSession, Server, ServeOptions, KeySource, ServerAuthConfig, etc).
Update Cargo.toml files with workspace-level package metadata
(version, edition, license, repository) and crate descriptions.
Adds client/connect.rs with ConnectOptions (programmatic API per ADR-011),
ClientSession::new() for SSH session establishment, ClientSession::run()
for SOCKS5 + port forwards + shutdown, and graceful shutdown via
SIGTERM/SIGINT with SSH disconnect and 2s drain timeout.
