checkpoint: implement wgcloak v1 foundations

examples/client.advanced.toml

@@ -0,0 +1,39 @@
+# Advanced client example. Values are placeholders, not credentials.
+
+[client]
+server = "vpn.example.invalid"
+id = "replace-me"
+secret_file = "/etc/wgcloak/client.secret"
+
+[local]
+listen = "127.0.0.1:51821"
+
+[transport]
+mode = "auto"
+
+# Auto probing is target behavior; use only transports supported by the build.
+[transport.auto]
+order = ["direct_udp", "quic", "http3", "tls_tcp"]
+probe_timeout_ms = 1500
+retries = 2
+
+[transport.direct_udp]
+port = 51830
+keepalive_secs = 15
+
+[transport.quic]
+port = 443
+keepalive_secs = 15
+
+[transport.http3]
+port = 443
+path = "/tunnel"
+
+[transport.tls_tcp]
+port = 443
+
+[network]
+max_datagram_size = 1200
+
+[logging]
+level = "info"