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/Cargo.toml

@@ -0,0 +1,44 @@
+[package]
+name = "alknet-core"
+version.workspace = true
+edition.workspace = true
+license.workspace = true
+description = "Core library for Alknet: pluggable SSH tunnel transport, SOCKS5 proxy, port forwarding, and authentication"
+repository.workspace = true
+
+[lib]
+name = "alknet_core"
+
+[features]
+default = []
+tls = ["dep:tokio-rustls", "dep:rustls", "dep:rustls-pki-types", "dep:webpki-roots"]
+iroh = ["dep:iroh", "dep:url"]
+acme = ["dep:rustls-acme", "dep:futures", "tls"]
+testutil = []
+transport-traits = []
+
+[dependencies]
+russh = "0.49"
+tokio = { version = "1", features = ["full"] }
+tracing = "0.1"
+anyhow = "1"
+thiserror = "2"
+tokio-util = { version = "0.7", features = ["compat"] }
+tokio-rustls = { version = "0.26", optional = true }
+rustls = { version = "0.23", optional = true, features = ["aws_lc_rs"] }
+rustls-pki-types = { version = "1", optional = true }
+rustls-acme = { version = "0.12", optional = true }
+futures = { version = "0.3", optional = true }
+webpki-roots = { version = "0.26", optional = true }
+iroh = { version = "0.34", optional = true }
+url = { version = "2", optional = true }
+async-trait = "0.1"
+ipnetwork = "0.21.1"
+
+[dev-dependencies]
+alknet-core = { path = ".", features = ["testutil", "tls", "iroh"] }
+tempfile = "3"
+rcgen = "0.14"
+rand_core = "0.6"
+ssh-key = { version = "0.6", features = ["ed25519", "alloc"] }
+rand = "0.10.1"