fix toggle task list display

[EasonMo]

When toggling display task list, it will only be displayed at the end of a large number of blank lines, and will not correctly display the effect of executing util.terminal_tail_hack().

The reason is that the execution order is wrong. The solution is to delay setting the buffer.

[stevearc]

This fix makes me a little nervous because it introduces some possible race conditions (what if the window is invalid? What if the buffer is deleted? What if something else switched this window's buffer?) Could you either find a way to fix it without the defer, or provide some repro steps so that I can investigate it myself?

[EasonMo]

Hi, I was a little careless. Now I have analyzed it carefully. The reason why it cannot be displayed correctly is that when calculating scroll lines, the SideBar window has not been generated yet, and terminal_tail_hack() has not been successfully executed. Therefore, TaskView:update() should be executed after the SideBar window is generated, rather than in TaskView:new() .What do you think?

[EasonMo]

Are there any updates regarding these questions?