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

peer_error.go

@@ -0,0 +1,151 @@
+package notify
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+)
+
+type detailedStateError struct {
+	base   error
+	detail string
+	cause  error
+}
+
+func (e *detailedStateError) Error() string {
+	if e == nil || e.base == nil {
+		return ""
+	}
+	base := e.base.Error()
+	detail := strings.TrimSpace(e.detail)
+	switch {
+	case detail != "" && e.cause != nil:
+		return fmt.Sprintf("%s: %s: %v", base, detail, e.cause)
+	case detail != "":
+		return fmt.Sprintf("%s: %s", base, detail)
+	case e.cause != nil:
+		return fmt.Sprintf("%s: %v", base, e.cause)
+	default:
+		return base
+	}
+}
+
+func (e *detailedStateError) Unwrap() error {
+	if e == nil {
+		return nil
+	}
+	return e.cause
+}
+
+func (e *detailedStateError) Is(target error) bool {
+	if e == nil {
+		return false
+	}
+	return target == e.base || errors.Is(e.cause, target)
+}
+
+func newDetailedStateError(base error, detail string, cause error) error {
+	if base == nil {
+		return cause
+	}
+	detail = strings.TrimSpace(detail)
+	if detail == "" && cause == nil {
+		return base
+	}
+	return &detailedStateError{
+		base:   base,
+		detail: detail,
+		cause:  cause,
+	}
+}
+
+func transportDetachedError(detail string, cause error) error {
+	return newDetailedStateError(errTransportDetached, detail, cause)
+}
+
+func clientTransportDetachedError(c *ClientCommon) error {
+	if c == nil {
+		return errTransportDetached
+	}
+	status := c.Status()
+	if status.Alive && c.clientTransportAttachedSnapshot() {
+		return errTransportDetached
+	}
+	switch status.Reason {
+	case "", "recv stop signal from user":
+		if status.Err != nil {
+			return transportDetachedError("", status.Err)
+		}
+		return errTransportDetached
+	default:
+		return transportDetachedError(status.Reason, status.Err)
+	}
+}
+
+func transportDetachedErrorForLogical(logical *LogicalConn) error {
+	if logical == nil {
+		return errTransportDetached
+	}
+	if detach := logical.transportDetachSnapshot(); detach != nil {
+		detail := strings.TrimSpace(detach.Reason)
+		if detach.Generation != 0 {
+			if detail == "" {
+				detail = fmt.Sprintf("generation=%d", detach.Generation)
+			} else {
+				detail = fmt.Sprintf("%s [generation=%d]", detail, detach.Generation)
+			}
+		}
+		if detach.Err != "" {
+			return transportDetachedError(detail, errors.New(detach.Err))
+		}
+		return transportDetachedError(detail, nil)
+	}
+	status := logical.Status()
+	if !status.Alive && (status.Reason != "" || status.Err != nil) {
+		return transportDetachedError(status.Reason, status.Err)
+	}
+	return errTransportDetached
+}
+
+func transportDetachedErrorForTransport(transport *TransportConn) error {
+	if transport == nil {
+		return errTransportDetached
+	}
+	if logical := transport.logicalConnSnapshot(); logical != nil {
+		if err := transportDetachedErrorForLogical(logical); err != errTransportDetached {
+			return err
+		}
+	}
+	switch {
+	case !transport.Attached():
+		return transportDetachedError(fmt.Sprintf("transport generation=%d not attached", transport.TransportGeneration()), nil)
+	case !transport.HasRuntimeConn():
+		return transportDetachedError(fmt.Sprintf("transport generation=%d has no runtime conn", transport.TransportGeneration()), nil)
+	case !transport.IsCurrent():
+		return transportDetachedError(fmt.Sprintf("stale transport generation=%d", transport.TransportGeneration()), nil)
+	default:
+		return errTransportDetached
+	}
+}
+
+func transportDetachedErrorForPeer(logical *LogicalConn, transport *TransportConn) error {
+	if transport != nil {
+		return transportDetachedErrorForTransport(transport)
+	}
+	return transportDetachedErrorForLogical(logical)
+}
+
+func transportDetachedGenerationMismatchError(expected uint64, transport *TransportConn) error {
+	actual := uint64(0)
+	if transport != nil {
+		actual = transport.TransportGeneration()
+	}
+	return transportDetachedError(
+		fmt.Sprintf("transport generation mismatch expected=%d actual=%d", expected, actual),
+		nil,
+	)
+}
+
+func transportDetachedSessionEpochError() error {
+	return transportDetachedError("stale client session epoch", nil)
+}