feat(notify): 重构通信内核并补齐 stream/bulk/record/transfer 能力

- 引入 LogicalConn/TransportConn 分层，ClientConn 保留兼容适配层
  - 新增 Stream、Bulk、RecordStream 三条数据面能力及对应控制路径
  - 完成 transfer/file 传输内核与状态快照、诊断能力
  - 补齐 reconnect、inbound dispatcher、modern psk 等基础模块
  - 增加大规模回归、并发与基准测试覆盖
  - 更新依赖库

internal/transport/stream.go

@@ -0,0 +1,79 @@
+package transport
+
+import (
+	"errors"
+	"net"
+	"strings"
+	"time"
+)
+
+var ErrNamedPipeUnsupported = errors.New("named pipe transport is only supported on windows")
+
+func IsUDPNetwork(network string) bool {
+	return strings.Contains(strings.ToLower(strings.TrimSpace(network)), "udp")
+}
+
+func IsNamedPipeNetwork(network string) bool {
+	switch strings.ToLower(strings.TrimSpace(network)) {
+	case "npipe", "pipe", "namedpipe", "named-pipe":
+		return true
+	default:
+		return false
+	}
+}
+
+func Dial(network string, addr string) (net.Conn, error) {
+	if IsNamedPipeNetwork(network) {
+		return dialNamedPipe(addr, nil)
+	}
+	return net.Dial(network, addr)
+}
+
+func DialTimeout(network string, addr string, timeout time.Duration) (net.Conn, error) {
+	if IsNamedPipeNetwork(network) {
+		return dialNamedPipe(addr, &timeout)
+	}
+	return net.DialTimeout(network, addr, timeout)
+}
+
+func Listen(network string, addr string) (net.Listener, error) {
+	if IsNamedPipeNetwork(network) {
+		return listenNamedPipe(addr)
+	}
+	return net.Listen(network, addr)
+}
+
+func NormalizeNamedPipeAddr(addr string) string {
+	trimmed := strings.TrimSpace(addr)
+	if trimmed == "" {
+		return trimmed
+	}
+	if strings.HasPrefix(trimmed, `\\.\pipe\`) {
+		return trimmed
+	}
+	if strings.HasPrefix(trimmed, `//./pipe/`) {
+		return `\\.\pipe\` + strings.TrimPrefix(trimmed, `//./pipe/`)
+	}
+	trimmed = strings.TrimPrefix(trimmed, `\\`)
+	trimmed = strings.TrimPrefix(trimmed, `//`)
+	trimmed = strings.TrimPrefix(trimmed, `.\pipe\`)
+	trimmed = strings.TrimPrefix(trimmed, `./pipe/`)
+	trimmed = strings.TrimPrefix(trimmed, `pipe\`)
+	trimmed = strings.TrimPrefix(trimmed, `pipe/`)
+	trimmed = strings.TrimLeft(strings.ReplaceAll(trimmed, "/", `\`), `\`)
+	return `\\.\pipe\` + trimmed
+}
+
+func ConnRemoteAddrString(conn net.Conn) string {
+	if conn == nil {
+		return "unknown"
+	}
+	addr := conn.RemoteAddr()
+	if addr == nil {
+		return "unknown"
+	}
+	if value := addr.String(); value != "" {
+		return value
+	}
+	return "unknown"
+}