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

stream_snapshot.go

@@ -0,0 +1,122 @@
+package notify
+
+import (
+	"errors"
+	"sort"
+	"time"
+)
+
+type StreamSnapshot struct {
+	ID                        string
+	DataID                    uint64
+	Scope                     string
+	Channel                   StreamChannel
+	Metadata                  StreamMetadata
+	BindingOwner              string
+	BindingAlive              bool
+	BindingCurrent            bool
+	BindingReason             string
+	BindingError              string
+	SessionEpoch              uint64
+	LogicalClientID           string
+	LocalAddress              string
+	RemoteAddress             string
+	TransportGeneration       uint64
+	TransportAttached         bool
+	TransportHasRuntimeConn   bool
+	TransportCurrent          bool
+	TransportDetachReason     string
+	TransportDetachKind       string
+	TransportDetachGeneration uint64
+	TransportDetachError      string
+	TransportDetachedAt       time.Time
+	ReattachEligible          bool
+	LocalClosed               bool
+	LocalReadClosed           bool
+	RemoteClosed              bool
+	PeerReadClosed            bool
+	BufferedChunks            int
+	BufferedBytes             int
+	ReadTimeout               time.Duration
+	WriteTimeout              time.Duration
+	BytesRead                 int64
+	BytesWritten              int64
+	ReadCalls                 int64
+	WriteCalls                int64
+	OpenedAt                  time.Time
+	LastReadAt                time.Time
+	LastWriteAt               time.Time
+	ReadDeadline              time.Time
+	WriteDeadline             time.Time
+	ResetError                string
+}
+
+type clientStreamSnapshotReader interface {
+	clientStreamSnapshots() []StreamSnapshot
+}
+
+type serverStreamSnapshotReader interface {
+	serverStreamSnapshots() []StreamSnapshot
+}
+
+var (
+	errClientStreamSnapshotNil         = errors.New("client stream snapshot target is nil")
+	errServerStreamSnapshotNil         = errors.New("server stream snapshot target is nil")
+	errClientStreamSnapshotUnsupported = errors.New("client stream snapshot target type is unsupported")
+	errServerStreamSnapshotUnsupported = errors.New("server stream snapshot target type is unsupported")
+)
+
+func GetClientStreamSnapshots(c Client) ([]StreamSnapshot, error) {
+	if c == nil {
+		return nil, errClientStreamSnapshotNil
+	}
+	reader, ok := any(c).(clientStreamSnapshotReader)
+	if !ok {
+		return nil, errClientStreamSnapshotUnsupported
+	}
+	return reader.clientStreamSnapshots(), nil
+}
+
+func GetServerStreamSnapshots(s Server) ([]StreamSnapshot, error) {
+	if s == nil {
+		return nil, errServerStreamSnapshotNil
+	}
+	reader, ok := any(s).(serverStreamSnapshotReader)
+	if !ok {
+		return nil, errServerStreamSnapshotUnsupported
+	}
+	return reader.serverStreamSnapshots(), nil
+}
+
+func (c *ClientCommon) clientStreamSnapshots() []StreamSnapshot {
+	return streamSnapshotsFromRuntime(c.getStreamRuntime())
+}
+
+func (s *ServerCommon) serverStreamSnapshots() []StreamSnapshot {
+	return streamSnapshotsFromRuntime(s.getStreamRuntime())
+}
+
+func streamSnapshotsFromRuntime(runtime *streamRuntime) []StreamSnapshot {
+	if runtime == nil {
+		return nil
+	}
+	return runtime.snapshots()
+}
+
+func sortStreamSnapshots(src []StreamSnapshot) {
+	sort.Slice(src, func(i, j int) bool {
+		if src[i].Scope != src[j].Scope {
+			return src[i].Scope < src[j].Scope
+		}
+		if src[i].ID != src[j].ID {
+			return src[i].ID < src[j].ID
+		}
+		if src[i].DataID != src[j].DataID {
+			return src[i].DataID < src[j].DataID
+		}
+		if src[i].TransportGeneration != src[j].TransportGeneration {
+			return src[i].TransportGeneration < src[j].TransportGeneration
+		}
+		return src[i].Channel < src[j].Channel
+	})
+}