feat: INP2P v0.1.0 — complete P2P tunneling system

Core modules (M1-M6):
- pkg/protocol: message format, encoding, NAT type enums
- pkg/config: server/client config structs, env vars, validation
- pkg/auth: CRC64 token, TOTP gen/verify, one-time relay tokens
- pkg/nat: UDP/TCP STUN client and server
- pkg/signal: WSS message dispatch, sync request/response
- pkg/punch: UDP/TCP hole punching + priority chain
- pkg/mux: stream multiplexer (7B frame: StreamID+Flags+Len)
- pkg/tunnel: mux-based port forwarding with stats
- pkg/relay: relay manager with TOTP auth + session bridging
- internal/server: signaling server (login/heartbeat/report/coordinator)
- internal/client: client (NAT detect/login/punch/relay/reconnect)
- cmd/inp2ps + cmd/inp2pc: main entrypoints with graceful shutdown

All tests pass: 16 tests across 5 packages
Code: 3559 lines core + 861 lines tests = 19 source files

cmd/inp2pc/main.go

@@ -0,0 +1,118 @@
+// inp2pc — INP2P P2P Client
+package main
+
+import (
+	"encoding/json"
+	"flag"
+	"fmt"
+	"log"
+	"os"
+	"os/signal"
+	"syscall"
+
+	"github.com/openp2p-cn/inp2p/internal/client"
+	"github.com/openp2p-cn/inp2p/pkg/auth"
+	"github.com/openp2p-cn/inp2p/pkg/config"
+)
+
+func main() {
+	cfg := config.DefaultClientConfig()
+
+	flag.StringVar(&cfg.ServerHost, "serverhost", "", "Server hostname or IP (required)")
+	flag.IntVar(&cfg.ServerPort, "serverport", cfg.ServerPort, "Server WSS port")
+	flag.StringVar(&cfg.Node, "node", "", "Node name (default: hostname)")
+	token := flag.Uint64("token", 0, "Authentication token (uint64)")
+	user := flag.String("user", "", "Username for token generation")
+	pass := flag.String("password", "", "Password for token generation")
+	flag.BoolVar(&cfg.Insecure, "insecure", false, "Skip TLS verification")
+	flag.BoolVar(&cfg.RelayEnabled, "relay", false, "Enable relay capability")
+	flag.BoolVar(&cfg.SuperRelay, "super", false, "Register as super relay node (implies -relay)")
+	flag.IntVar(&cfg.RelayPort, "relay-port", cfg.RelayPort, "Relay listen port")
+	flag.IntVar(&cfg.MaxRelayLoad, "relay-max", cfg.MaxRelayLoad, "Max concurrent relay sessions")
+	flag.IntVar(&cfg.ShareBandwidth, "bw", cfg.ShareBandwidth, "Share bandwidth (Mbps)")
+	flag.IntVar(&cfg.STUNUDP1, "stun-udp1", cfg.STUNUDP1, "UDP STUN port 1")
+	flag.IntVar(&cfg.STUNUDP2, "stun-udp2", cfg.STUNUDP2, "UDP STUN port 2")
+	flag.IntVar(&cfg.STUNTCP1, "stun-tcp1", cfg.STUNTCP1, "TCP STUN port 1")
+	flag.IntVar(&cfg.STUNTCP2, "stun-tcp2", cfg.STUNTCP2, "TCP STUN port 2")
+	flag.IntVar(&cfg.LogLevel, "log-level", cfg.LogLevel, "Log level")
+	configFile := flag.String("config", "config.json", "Config file path")
+	newConfig := flag.Bool("newconfig", false, "Ignore existing config, use command line args only")
+	version := flag.Bool("version", false, "Print version and exit")
+	flag.Parse()
+
+	if *version {
+		fmt.Printf("inp2pc version %s\n", config.Version)
+		os.Exit(0)
+	}
+
+	// Load config file first (unless -newconfig)
+	if !*newConfig {
+		if data, err := os.ReadFile(*configFile); err == nil {
+			var fileCfg config.ClientConfig
+			if err := json.Unmarshal(data, &fileCfg); err == nil {
+				cfg = fileCfg
+				log.Printf("[main] loaded config from %s", *configFile)
+			}
+		}
+	}
+
+	// Command line flags override config file
+	flag.Visit(func(f *flag.Flag) {
+		switch f.Name {
+		case "serverhost":
+			cfg.ServerHost = f.Value.String()
+		case "serverport":
+			fmt.Sscanf(f.Value.String(), "%d", &cfg.ServerPort)
+		case "node":
+			cfg.Node = f.Value.String()
+		case "insecure":
+			cfg.Insecure = true
+		case "relay":
+			cfg.RelayEnabled = true
+		case "super":
+			cfg.SuperRelay = true
+			cfg.RelayEnabled = true // super implies relay
+		case "bw":
+			fmt.Sscanf(f.Value.String(), "%d", &cfg.ShareBandwidth)
+		}
+	})
+
+	// Token from flag or credentials
+	if *token > 0 {
+		cfg.Token = *token
+	} else if *user != "" && *pass != "" {
+		cfg.Token = auth.MakeToken(*user, *pass)
+		log.Printf("[main] token: %d", cfg.Token)
+	}
+
+	if err := cfg.Validate(); err != nil {
+		log.Fatalf("[main] config error: %v", err)
+	}
+
+	log.Printf("[main] inp2pc v%s starting", config.Version)
+	log.Printf("[main] node=%s server=%s:%d relay=%v super=%v",
+		cfg.Node, cfg.ServerHost, cfg.ServerPort, cfg.RelayEnabled, cfg.SuperRelay)
+
+	// Save config
+	if data, err := json.MarshalIndent(cfg, "", "  "); err == nil {
+		os.WriteFile(*configFile, data, 0644)
+	}
+
+	// Create and run client
+	c := client.New(cfg)
+
+	// Handle shutdown
+	sigCh := make(chan os.Signal, 1)
+	signal.Notify(sigCh, syscall.SIGINT, syscall.SIGTERM)
+	go func() {
+		<-sigCh
+		log.Println("[main] shutting down...")
+		c.Stop()
+	}()
+
+	if err := c.Run(); err != nil {
+		log.Fatalf("[main] client error: %v", err)
+	}
+
+	log.Println("[main] goodbye")
+}