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

signal_ack_test.go

@@ -0,0 +1,33 @@
+package notify
+
+import "testing"
+
+func TestSignalAckPoolPreparedWaitConsumesAck(t *testing.T) {
+	pool := newSignalAckPool()
+	wait := pool.prepare("client", 1001)
+
+	if ok := pool.deliver("client", 1001); !ok {
+		t.Fatal("deliver should match prepared signal waiter")
+	}
+	if err := pool.waitPrepared(wait, defaultSignalAckTimeout); err != nil {
+		t.Fatalf("waitPrepared failed: %v", err)
+	}
+}
+
+func TestSignalAckPoolCloseScopeCancelsMatchingWaiter(t *testing.T) {
+	pool := newSignalAckPool()
+	waitA := pool.prepare("server:client-a", 1002)
+	waitB := pool.prepare("server:client-b", 1002)
+
+	pool.closeScope("server:client-a")
+
+	if err := pool.waitPrepared(waitA, defaultSignalAckTimeout); err == nil || err.Error() != "signal ack canceled" {
+		t.Fatalf("scopeA cancel mismatch: %v", err)
+	}
+	if ok := pool.deliver("server:client-b", 1002); !ok {
+		t.Fatal("scopeB waiter should remain deliverable")
+	}
+	if err := pool.waitPrepared(waitB, defaultSignalAckTimeout); err != nil {
+		t.Fatalf("waitPrepared scopeB failed: %v", err)
+	}
+}