feat(client): implement alknet-client crate — AlknetClient, dial methods, error type, SOCKS5 proxy

- Initialize alknet-client crate with Cargo.toml, deps, feature flags
- Implement ClientDialError enum with 5 variants (TlsConfig, Connect, Handshake, NoTransport, Proxy)
- Implement AlknetClient struct with builder methods (with_quinn, with_tcp_tls, with_iroh, with_socks5_proxy)
- Implement dial_quic — QUIC dial via quinn, producing a Connection
- Implement dial_tcp_tls — TCP+TLS dial via tokio-rustls, producing a Connection
- Implement dial_iroh — iroh dial, producing a Connection
- Implement SOCKS5 proxy support — Socks5ProxyConfig, Socks5Credentials, Socks5UdpSocket, proxy integration
- Add into_rustls_config() to TlsClientConfig in alknet-tls
- Add alknet-client to workspace members

Tasks: client/crate-init, client/error-type, client/client-core,
client/dial-quic, client/dial-tcp-tls, client/dial-iroh, client/socks5-proxy

Cargo.lock

@@ -68,6 +68,24 @@ dependencies = [
  "uuid",
 ]
 
+[[package]]
+name = "alknet-client"
+version = "0.1.0"
+dependencies = [
+ "alknet-core",
+ "alknet-tls",
+ "fast-socks5",
+ "hex",
+ "iroh",
+ "quinn",
+ "rustls",
+ "rustls-pki-types",
+ "thiserror 2.0.18",
+ "tokio",
+ "tokio-rustls",
+ "tracing",
+]
+
 [[package]]
 name = "alknet-core"
 version = "0.1.0"
@@ -1296,6 +1314,21 @@ dependencies = [
  "pin-project-lite",
 ]
 
+[[package]]
+name = "fast-socks5"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9545787d8304a71e1bf1b711705070a4c400cce9b332c4a11800627b7c9a2067"
+dependencies = [
+ "anyhow",
+ "async-trait",
+ "log",
+ "socket2 0.5.10",
+ "thiserror 1.0.69",
+ "tokio",
+ "tokio-stream",
+]
+
 [[package]]
 name = "fastbloom"
 version = "0.14.1"
@@ -1834,7 +1867,7 @@ dependencies = [
  "libc",
  "percent-encoding",
  "pin-project-lite",
- "socket2",
+ "socket2 0.6.4",
  "tokio",
  "tower-service",
  "tracing",
@@ -2006,7 +2039,7 @@ version = "0.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4d40460c0ce33d6ce4b0630ad68ff63d6661961c48b6dba35e5a4d81cfb48222"
 dependencies = [
- "socket2",
+ "socket2 0.6.4",
  "widestring",
  "windows-registry",
  "windows-result",
@@ -2595,7 +2628,7 @@ dependencies = [
  "objc2-system-configuration",
  "pin-project-lite",
  "serde",
- "socket2",
+ "socket2 0.6.4",
  "time",
  "tokio",
  "tokio-util",
@@ -2642,7 +2675,7 @@ dependencies = [
  "pin-project-lite",
  "rustc-hash",
  "rustls",
- "socket2",
+ "socket2 0.6.4",
  "thiserror 2.0.18",
  "tokio",
  "tokio-stream",
@@ -2685,7 +2718,7 @@ checksum = "3137a52df66c20090a889828d1c655f21f52294cba64e5c4fbb04fc83eee7c8e"
 dependencies = [
  "cfg_aliases 0.2.1",
  "libc",
- "socket2",
+ "socket2 0.6.4",
  "tracing",
  "windows-sys 0.61.2",
 ]
@@ -3213,7 +3246,7 @@ dependencies = [
  "quinn-udp",
  "rustc-hash",
  "rustls",
- "socket2",
+ "socket2 0.6.4",
  "thiserror 2.0.18",
  "tokio",
  "tracing",
@@ -3253,7 +3286,7 @@ dependencies = [
  "cfg_aliases 0.2.1",
  "libc",
  "once_cell",
- "socket2",
+ "socket2 0.6.4",
  "tracing",
  "windows-sys 0.60.2",
 ]
@@ -4093,6 +4126,16 @@ version = "1.15.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8ed6a63f02c8539c91a8685a86f4099661ba3da017932f6ebbea6de3f0fa7c90"
 
+[[package]]
+name = "socket2"
+version = "0.5.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e22376abed350d73dd1cd119b57ffccad95b4e585a7cda43e286245ce23c0678"
+dependencies = [
+ "libc",
+ "windows-sys 0.52.0",
+]
+
 [[package]]
 name = "socket2"
 version = "0.6.4"
@@ -4388,7 +4431,7 @@ dependencies = [
  "parking_lot",
  "pin-project-lite",
  "signal-hook-registry",
- "socket2",
+ "socket2 0.6.4",
  "tokio-macros",
  "windows-sys 0.61.2",
 ]