Initial vibeproxy implementation

Self-contained HTTP/HTTPS/TCP/UDP reverse proxy manager written in Go,
with SQLite storage, a Bootstrap 5 admin UI (Go templates, no JS
framework), and a REST API under /api/v1.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QTXFrNP1imCW7jtfL5SZrw

internal/streams/tcp_test.go

@@ -0,0 +1,96 @@
+package streams
+
+import (
+	"context"
+	"io"
+	"log/slog"
+	"net"
+	"testing"
+	"time"
+
+	"github.com/owen/vibeproxy/internal/models"
+)
+
+func TestTCPProxyEndToEnd(t *testing.T) {
+	// Echo backend.
+	backendLn, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer backendLn.Close()
+	go func() {
+		for {
+			c, err := backendLn.Accept()
+			if err != nil {
+				return
+			}
+			go func() {
+				defer c.Close()
+				io.Copy(c, c)
+			}()
+		}
+	}()
+
+	backendAddr := backendLn.Addr().(*net.TCPAddr)
+	model := models.Stream{
+		Protocol: models.StreamTCP, ListenIP: "127.0.0.1", ListenPort: 0,
+		DestinationHost: "127.0.0.1", DestinationPort: backendAddr.Port,
+		ConnectTimeoutMS: 2000, IdleTimeoutMS: 5000,
+	}
+
+	// Bind an ephemeral port ourselves so we know it up front, matching
+	// what NewTCPProxy will do.
+	probe, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatal(err)
+	}
+	model.ListenPort = probe.Addr().(*net.TCPAddr).Port
+	probe.Close()
+
+	log := slog.New(slog.NewTextHandler(io.Discard, nil))
+	proxy := NewTCPProxy(model, log)
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	if err := proxy.Start(ctx); err != nil {
+		t.Fatal(err)
+	}
+	defer proxy.Stop()
+
+	time.Sleep(50 * time.Millisecond)
+	conn, err := net.Dial("tcp", net.JoinHostPort("127.0.0.1", itoa(model.ListenPort)))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer conn.Close()
+
+	if _, err := conn.Write([]byte("ping")); err != nil {
+		t.Fatal(err)
+	}
+	conn.SetReadDeadline(time.Now().Add(2 * time.Second))
+	buf := make([]byte, 4)
+	if _, err := io.ReadFull(conn, buf); err != nil {
+		t.Fatal(err)
+	}
+	if string(buf) != "ping" {
+		t.Fatalf("expected echo of ping, got %q", buf)
+	}
+}
+
+func itoa(n int) string {
+	if n == 0 {
+		return "0"
+	}
+	neg := n < 0
+	if neg {
+		n = -n
+	}
+	var b []byte
+	for n > 0 {
+		b = append([]byte{byte('0' + n%10)}, b...)
+		n /= 10
+	}
+	if neg {
+		b = append([]byte{'-'}, b...)
+	}
+	return string(b)
+}