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-core/src/server/mod.rs

@@ -0,0 +1,25 @@
+//! Server-side SSH connection handling.
+//!
+//! Provides `Server` for accepting SSH connections over any transport and proxying
+//! `direct-tcpip` channel requests to targets. Supports Ed25519 and certificate-authority
+//! auth, connection rate limiting, auth attempt limiting, stealth mode (fake nginx 404),
+//! and outbound proxy routing (direct/SOCKS5/HTTP CONNECT).
+//!
+//! Destination hosts starting with `alknet-` are reserved for internal use (control channel, ADR-018).
+
+pub mod channel_proxy;
+pub mod control_channel;
+pub mod handler;
+pub mod rate_limit;
+pub mod serve;
+pub mod stealth;
+
+pub use channel_proxy::{connect_outbound, proxy_channel};
+pub use control_channel::{
+    ControlChannelHandler, ControlChannelRouter, DuplexStream, ALKNET_CONTROL_DESTINATION,
+    ALKNET_PREFIX, is_reserved_destination,
+};
+pub use handler::{ProxyConfig, ProxyMode, ServerHandler, TransportKind};
+pub use rate_limit::{AuthAttemptLimiter, ConnectionRateLimiter};
+pub use serve::{Server, ServeError, ServeOptions, ServeTransportMode};
+pub use stealth::{ProtocolDetection, detect_protocol, send_fake_nginx_404, validate_stealth_config};