feat(transport): 完成安全架构拆分并收口 stream/bulk 传输优化

- 新增 managed/external/nested 三种传输保护模式
  - 新增 peer attach 显式认证、抗重放、channel binding 和可选前向保密协商
  - 明确单连接注入与可重拨连接源的语义边界
  - 禁止 ConnectByConn 场景下 dedicated bulk 走 sidecar，auto 模式自动回退 shared
  - 修正 dedicated attach 在 bootstrap/steady profile 切换下的处理逻辑
  - 优化 shared bulk super-batch 与批量 framed write 路径
  - 降低 stream/bulk fast path 的复制和分发损耗
  - 补齐 benchmark、回归测试、运行时快照和 README 文档

client_runtime.go

@@ -350,6 +350,8 @@ func (c *ClientCommon) bootstrapClientTransportRuntime(rt *clientSessionRuntime,
 	if rt == nil {
 		return nil
 	}
+	c.resetClientPeerAttachAuth()
+	c.activateClientBootstrapTransportProtection()
 	if runKeyExchange && !c.skipKeyExchange {
 		if err := c.keyExchangeFn(c); err != nil {
 			return c.failClientTransportBootstrap(rt, stopSessionOnFailure, "key exchange failed", err)
@@ -358,6 +360,7 @@ func (c *ClientCommon) bootstrapClientTransportRuntime(rt *clientSessionRuntime,
 	if err := c.announceClientPeerIdentity(); err != nil {
 		return c.failClientTransportBootstrap(rt, stopSessionOnFailure, "peer attach failed", err)
 	}
+	c.activateClientSteadyTransportProtection()
 	return nil
 }